Reland "[riscv32] Add RISCV32 backend"

This is a reland of commit 491de34b

co-authors: Ji Qiu <qiuji@iscas.ac.cn>
            Alvise De Faveri Tron <elvisilde@gmail.com>
            Usman Zain <uszain@gmail.com>
            Zheng Quan <vitalyankh@gmail.com>

Original change's description:
> [riscv32] Add RISCV32 backend
>
> This very large changeset adds support for RISCV32.
>
> Bug: v8:13025
> Change-Id: Ieacc857131e6620f0fcfd7daa88a0f8d77056aa9
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3736732
> Reviewed-by: Michael Achenbach <machenbach@chromium.org>
> Commit-Queue: Yahan Lu <yahan@iscas.ac.cn>
> Reviewed-by: ji qiu <qiuji@iscas.ac.cn>
> Reviewed-by: Andreas Haas <ahaas@chromium.org>
> Reviewed-by: Hannes Payer <hpayer@chromium.org>
> Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#82053}

Bug: v8:13025
Change-Id: I220fae4b8e2679bdc111724e08817b079b373bd5
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3807124
Commit-Queue: Yahan Lu <yahan@iscas.ac.cn>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: ji qiu <qiuji@iscas.ac.cn>
Reviewed-by: Hannes Payer <hpayer@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/main@{#82198}

OWNERS

@@ -27,5 +27,5 @@ per-file ...-loong64*=file:LOONG_OWNERS
 per-file ...-mips*=file:MIPS_OWNERS
 per-file ...-mips64*=file:MIPS_OWNERS
 per-file ...-ppc*=file:PPC_OWNERS
-per-file ...-riscv64*=file:RISCV_OWNERS
+per-file ...-riscv*=file:RISCV_OWNERS
 per-file ...-s390*=file:S390_OWNERS

gni/snapshot_toolchain.gni

@@ -96,7 +96,8 @@ if (v8_snapshot_toolchain == "") {
       } else {
         _cpus = "x64_v8_${v8_current_cpu}"
       }
-    } else if (v8_current_cpu == "arm" || v8_current_cpu == "mipsel") {
+    } else if (v8_current_cpu == "arm" || v8_current_cpu == "mipsel" ||
+               v8_current_cpu == "riscv32") {
       _cpus = "x86_v8_${v8_current_cpu}"
     } else {
       # This branch should not be reached; leave _cpus blank so the assert

include/v8-unwinder-state.h

@@ -20,7 +20,7 @@ struct CalleeSavedRegisters {
 #elif V8_TARGET_ARCH_X64 || V8_TARGET_ARCH_IA32 || V8_TARGET_ARCH_ARM64 ||   \
     V8_TARGET_ARCH_MIPS || V8_TARGET_ARCH_MIPS64 || V8_TARGET_ARCH_PPC ||    \
     V8_TARGET_ARCH_PPC64 || V8_TARGET_ARCH_RISCV64 || V8_TARGET_ARCH_S390 || \
-    V8_TARGET_ARCH_LOONG64
+    V8_TARGET_ARCH_LOONG64 || V8_TARGET_ARCH_RISCV32
 struct CalleeSavedRegisters {};
 #else
 #error Target architecture was not detected as supported by v8

include/v8config.h

@@ -674,6 +674,9 @@ V8 shared library set USING_V8_SHARED.
 #if __riscv_xlen == 64
 #define V8_HOST_ARCH_RISCV64 1
 #define V8_HOST_ARCH_64_BIT 1
+#elif __riscv_xlen == 32
+#define V8_HOST_ARCH_RISCV32 1
+#define V8_HOST_ARCH_32_BIT 1
 #else
 #error "Cannot detect Riscv's bitwidth"
 #endif
@@ -689,7 +692,8 @@ V8 shared library set USING_V8_SHARED.
 #if !V8_TARGET_ARCH_X64 && !V8_TARGET_ARCH_IA32 && !V8_TARGET_ARCH_ARM &&      \
     !V8_TARGET_ARCH_ARM64 && !V8_TARGET_ARCH_MIPS && !V8_TARGET_ARCH_MIPS64 && \
     !V8_TARGET_ARCH_PPC && !V8_TARGET_ARCH_PPC64 && !V8_TARGET_ARCH_S390 &&    \
-    !V8_TARGET_ARCH_RISCV64 && !V8_TARGET_ARCH_LOONG64
+    !V8_TARGET_ARCH_RISCV64 && !V8_TARGET_ARCH_LOONG64 &&                      \
+    !V8_TARGET_ARCH_RISCV32
 #if defined(_M_X64) || defined(__x86_64__)
 #define V8_TARGET_ARCH_X64 1
 #elif defined(_M_IX86) || defined(__i386__)
@@ -714,6 +718,8 @@ V8 shared library set USING_V8_SHARED.
 #elif defined(__riscv) || defined(__riscv__)
 #if __riscv_xlen == 64
 #define V8_TARGET_ARCH_RISCV64 1
+#elif __riscv_xlen == 32
+#define V8_TARGET_ARCH_RISCV32 1
 #endif
 #else
 #error Target architecture was not detected as supported by v8
@@ -753,6 +759,8 @@ V8 shared library set USING_V8_SHARED.
 #endif
 #elif V8_TARGET_ARCH_RISCV64
 #define V8_TARGET_ARCH_64_BIT 1
+#elif V8_TARGET_ARCH_RISCV32
+#define V8_TARGET_ARCH_32_BIT 1
 #else
 #error Unknown target architecture pointer size
 #endif
@@ -784,6 +792,9 @@ V8 shared library set USING_V8_SHARED.
 #if (V8_TARGET_ARCH_RISCV64 && !(V8_HOST_ARCH_X64 || V8_HOST_ARCH_RISCV64))
 #error Target architecture riscv64 is only supported on riscv64 and x64 host
 #endif
+#if (V8_TARGET_ARCH_RISCV32 && !(V8_HOST_ARCH_IA32 || V8_HOST_ARCH_RISCV32))
+#error Target architecture riscv32 is only supported on riscv32 and ia32 host
+#endif
 #if (V8_TARGET_ARCH_LOONG64 && !(V8_HOST_ARCH_X64 || V8_HOST_ARCH_LOONG64))
 #error Target architecture loong64 is only supported on loong64 and x64 host
 #endif
@@ -823,7 +834,7 @@ V8 shared library set USING_V8_SHARED.
 #else
 #define V8_TARGET_BIG_ENDIAN 1
 #endif
-#elif V8_TARGET_ARCH_RISCV64
+#elif V8_TARGET_ARCH_RISCV32 || V8_TARGET_ARCH_RISCV64
 #define V8_TARGET_LITTLE_ENDIAN 1
 #elif defined(__BYTE_ORDER__)
 #if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__

src/base/compiler-specific.h

@@ -98,10 +98,10 @@
 // do not support adding noexcept to default members.
 // Disabled on MSVC because constructors of standard containers are not noexcept
 // there.
-#if ((!defined(V8_CC_GNU) && !defined(V8_CC_MSVC) &&                      \
-      !defined(V8_TARGET_ARCH_MIPS) && !defined(V8_TARGET_ARCH_MIPS64) && \
-      !defined(V8_TARGET_ARCH_PPC) && !defined(V8_TARGET_ARCH_PPC64) &&   \
-      !defined(V8_TARGET_ARCH_RISCV64)) ||                                \
+#if ((!defined(V8_CC_GNU) && !defined(V8_CC_MSVC) &&                           \
+      !defined(V8_TARGET_ARCH_MIPS) && !defined(V8_TARGET_ARCH_MIPS64) &&      \
+      !defined(V8_TARGET_ARCH_PPC) && !defined(V8_TARGET_ARCH_PPC64) &&        \
+      !defined(V8_TARGET_ARCH_RISCV64) && !defined(V8_TARGET_ARCH_RISCV32)) || \
      (defined(__clang__) && __cplusplus > 201300L))
 #define V8_NOEXCEPT noexcept
 #else

src/base/platform/platform-posix.cc

@@ -354,6 +354,10 @@ void* OS::GetRandomMmapAddr() {
   // TODO(RISCV): We need more information from the kernel to correctly mask
   // this address for RISC-V. https://github.com/v8-riscv/v8/issues/375
   raw_addr &= uint64_t{0xFFFFFF0000};
+#elif V8_TARGET_ARCH_RISCV32
+  // TODO(RISCV): We need more information from the kernel to correctly mask
+  // this address for RISC-V. https://github.com/v8-riscv/v8/issues/375
+  raw_addr &= 0x3FFFF000;
 #elif V8_TARGET_ARCH_LOONG64
   // 42 bits of virtual addressing. Truncate to 40 bits to allow kernel chance
   // to fulfill request.
@@ -685,6 +689,8 @@ void OS::DebugBreak() {
   asm volatile(".word 0x0001");
 #elif V8_HOST_ARCH_RISCV64
   asm("ebreak");
+#elif V8_HOST_ARCH_RISCV32
+  asm("ebreak");
 #else
 #error Unsupported host architecture.
 #endif

src/baseline/baseline-assembler-inl.h

@@ -32,8 +32,8 @@
 #include "src/baseline/ppc/baseline-assembler-ppc-inl.h"
 #elif V8_TARGET_ARCH_S390X
 #include "src/baseline/s390/baseline-assembler-s390-inl.h"
-#elif V8_TARGET_ARCH_RISCV64
-#include "src/baseline/riscv64/baseline-assembler-riscv64-inl.h"
+#elif V8_TARGET_ARCH_RISCV32 || V8_TARGET_ARCH_RISCV64
+#include "src/baseline/riscv/baseline-assembler-riscv-inl.h"
 #elif V8_TARGET_ARCH_MIPS64
 #include "src/baseline/mips64/baseline-assembler-mips64-inl.h"
 #elif V8_TARGET_ARCH_MIPS

src/baseline/baseline-compiler.cc

@@ -48,7 +48,9 @@
 #elif V8_TARGET_ARCH_S390X
 #include "src/baseline/s390/baseline-compiler-s390-inl.h"
 #elif V8_TARGET_ARCH_RISCV64
-#include "src/baseline/riscv64/baseline-compiler-riscv64-inl.h"
+#include "src/baseline/riscv/baseline-compiler-riscv-inl.h"
+#elif V8_TARGET_ARCH_RISCV32
+#include "src/baseline/riscv/baseline-compiler-riscv-inl.h"
 #elif V8_TARGET_ARCH_MIPS64
 #include "src/baseline/mips64/baseline-compiler-mips64-inl.h"
 #elif V8_TARGET_ARCH_MIPS

src/baseline/riscv64/baseline-assembler-riscv64-inl.h → src/baseline/riscv/baseline-assembler-riscv-inl.h

@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef V8_BASELINE_RISCV64_BASELINE_ASSEMBLER_RISCV64_INL_H_
-#define V8_BASELINE_RISCV64_BASELINE_ASSEMBLER_RISCV64_INL_H_
+#ifndef V8_BASELINE_RISCV_BASELINE_ASSEMBLER_RISCV_INL_H_
+#define V8_BASELINE_RISCV_BASELINE_ASSEMBLER_RISCV_INL_H_
 
 #include "src/baseline/baseline-assembler.h"
 #include "src/codegen/assembler-inl.h"
@@ -79,8 +79,8 @@ MemOperand BaselineAssembler::RegisterFrameOperand(
 }
 void BaselineAssembler::RegisterFrameAddress(
     interpreter::Register interpreter_register, Register rscratch) {
-  return __ Add64(rscratch, fp,
-                  interpreter_register.ToOperand() * kSystemPointerSize);
+  return __ AddWord(rscratch, fp,
+                    interpreter_register.ToOperand() * kSystemPointerSize);
 }
 MemOperand BaselineAssembler::FeedbackVectorOperand() {
   return MemOperand(fp, BaselineFrameConstants::kFeedbackVectorFromFp);
@@ -163,7 +163,7 @@ void BaselineAssembler::JumpIfInstanceType(Condition cc, Register map,
     __ GetObjectType(map, type, type);
     __ Assert(eq, AbortReason::kUnexpectedValue, type, Operand(MAP_TYPE));
   }
-  __ Ld(type, FieldMemOperand(map, Map::kInstanceTypeOffset));
+  __ LoadWord(type, FieldMemOperand(map, Map::kInstanceTypeOffset));
   __ Branch(target, AsMasmCondition(cc), type, Operand(instance_type));
 }
 void BaselineAssembler::JumpIfPointer(Condition cc, Register value,
@@ -171,7 +171,7 @@ void BaselineAssembler::JumpIfPointer(Condition cc, Register value,
                                       Label::Distance) {
   ScratchRegisterScope temps(this);
   Register temp = temps.AcquireScratch();
-  __ Ld(temp, operand);
+  __ LoadWord(temp, operand);
   __ Branch(target, AsMasmCondition(cc), value, Operand(temp));
 }
 void BaselineAssembler::JumpIfSmi(Condition cc, Register value, Smi smi,
@@ -195,7 +195,7 @@ void BaselineAssembler::JumpIfTagged(Condition cc, Register value,
   // todo: compress pointer
   ScratchRegisterScope temps(this);
   Register scratch = temps.AcquireScratch();
-  __ Ld(scratch, operand);
+  __ LoadWord(scratch, operand);
   __ Branch(target, AsMasmCondition(cc), value, Operand(scratch));
 }
 void BaselineAssembler::JumpIfTagged(Condition cc, MemOperand operand,
@@ -204,7 +204,7 @@ void BaselineAssembler::JumpIfTagged(Condition cc, MemOperand operand,
   // todo: compress pointer
   ScratchRegisterScope temps(this);
   Register scratch = temps.AcquireScratch();
-  __ Ld(scratch, operand);
+  __ LoadWord(scratch, operand);
   __ Branch(target, AsMasmCondition(cc), scratch, Operand(value));
 }
 void BaselineAssembler::JumpIfByte(Condition cc, Register value, int32_t byte,
@@ -219,7 +219,7 @@ void BaselineAssembler::Move(Register output, TaggedIndex value) {
   __ li(output, Operand(value.ptr()));
 }
 void BaselineAssembler::Move(MemOperand output, Register source) {
-  __ Sd(source, output);
+  __ StoreWord(source, output);
 }
 void BaselineAssembler::Move(Register output, ExternalReference reference) {
   __ li(output, Operand(reference));
@@ -446,8 +446,9 @@ void BaselineAssembler::AddToInterruptBudgetAndJumpIfNotExceeded(
   __ Add32(interrupt_budget, interrupt_budget, weight);
   __ Sw(interrupt_budget,
         FieldMemOperand(feedback_cell, FeedbackCell::kInterruptBudgetOffset));
-  if (skip_interrupt_label)
+  if (skip_interrupt_label) {
     __ Branch(skip_interrupt_label, ge, interrupt_budget, Operand(zero_reg));
+  }
 }
 
 void BaselineAssembler::LdaContextSlot(Register context, uint32_t index,
@@ -510,27 +511,26 @@ void BaselineAssembler::AddSmi(Register lhs, Smi rhs) {
   if (SmiValuesAre31Bits()) {
     __ Add32(lhs, lhs, Operand(rhs));
   } else {
-    __ Add64(lhs, lhs, Operand(rhs));
+    __ AddWord(lhs, lhs, Operand(rhs));
   }
 }
 
 void BaselineAssembler::Word32And(Register output, Register lhs, int rhs) {
   __ And(output, lhs, Operand(rhs));
 }
-
 void BaselineAssembler::Switch(Register reg, int case_value_base,
                                Label** labels, int num_labels) {
   ASM_CODE_COMMENT(masm_);
   Label fallthrough;
   if (case_value_base != 0) {
-    __ Sub64(reg, reg, Operand(case_value_base));
+    __ SubWord(reg, reg, Operand(case_value_base));
   }
 
   // Mostly copied from code-generator-riscv64.cc
   ScratchRegisterScope scope(this);
   Label table;
   __ Branch(&fallthrough, AsMasmCondition(Condition::kUnsignedGreaterThanEqual),
-            reg, Operand(int64_t(num_labels)));
+            reg, Operand(num_labels));
   int64_t imm64;
   imm64 = __ branch_long_offset(&table);
   CHECK(is_int32(imm64 + 0x800));
@@ -619,4 +619,4 @@ inline void EnsureAccumulatorPreservedScope::AssertEqualToAccumulator(
 }  // namespace internal
 }  // namespace v8
 
-#endif  // V8_BASELINE_RISCV64_BASELINE_ASSEMBLER_RISCV64_INL_H_
+#endif  // V8_BASELINE_RISCV_BASELINE_ASSEMBLER_RISCV_INL_H_

src/baseline/riscv64/baseline-compiler-riscv64-inl.h → src/baseline/riscv/baseline-compiler-riscv-inl.h

@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef V8_BASELINE_RISCV64_BASELINE_COMPILER_RISCV64_INL_H_
-#define V8_BASELINE_RISCV64_BASELINE_COMPILER_RISCV64_INL_H_
+#ifndef V8_BASELINE_RISCV_BASELINE_COMPILER_RISCV_INL_H_
+#define V8_BASELINE_RISCV_BASELINE_COMPILER_RISCV_INL_H_
 
 #include "src/baseline/baseline-compiler.h"
 
@@ -39,10 +39,10 @@ void BaselineCompiler::PrologueFillFrame() {
   const bool has_new_target = new_target_index != kMaxInt;
   if (has_new_target) {
     DCHECK_LE(new_target_index, register_count);
-    __ masm()->Add64(sp, sp, Operand(-(kPointerSize * new_target_index)));
+    __ masm()->AddWord(sp, sp, Operand(-(kPointerSize * new_target_index)));
     for (int i = 0; i < new_target_index; i++) {
-      __ masm()->Sd(kInterpreterAccumulatorRegister,
-                    MemOperand(sp, i * kSystemPointerSize));
+      __ masm()->StoreWord(kInterpreterAccumulatorRegister,
+                           MemOperand(sp, i * kSystemPointerSize));
     }
     // Push new_target_or_generator.
     __ Push(kJavaScriptCallNewTargetRegister);
@@ -50,25 +50,25 @@ void BaselineCompiler::PrologueFillFrame() {
   }
   if (register_count < 2 * kLoopUnrollSize) {
     // If the frame is small enough, just unroll the frame fill completely.
-    __ masm()->Add64(sp, sp, Operand(-(kPointerSize * register_count)));
+    __ masm()->AddWord(sp, sp, Operand(-(kPointerSize * register_count)));
     for (int i = 0; i < register_count; ++i) {
-      __ masm()->Sd(kInterpreterAccumulatorRegister,
-                    MemOperand(sp, i * kSystemPointerSize));
+      __ masm()->StoreWord(kInterpreterAccumulatorRegister,
+                           MemOperand(sp, i * kSystemPointerSize));
     }
   } else {
-    __ masm()->Add64(sp, sp, Operand(-(kPointerSize * register_count)));
+    __ masm()->AddWord(sp, sp, Operand(-(kPointerSize * register_count)));
     for (int i = 0; i < register_count; ++i) {
-      __ masm()->Sd(kInterpreterAccumulatorRegister,
-                    MemOperand(sp, i * kSystemPointerSize));
+      __ masm()->StoreWord(kInterpreterAccumulatorRegister,
+                           MemOperand(sp, i * kSystemPointerSize));
     }
   }
 }
 
 void BaselineCompiler::VerifyFrameSize() {
   ASM_CODE_COMMENT(&masm_);
-  __ masm()->Add64(kScratchReg, sp,
-                   Operand(InterpreterFrameConstants::kFixedFrameSizeFromFp +
-                           bytecode_->frame_size()));
+  __ masm()->AddWord(kScratchReg, sp,
+                     Operand(InterpreterFrameConstants::kFixedFrameSizeFromFp +
+                             bytecode_->frame_size()));
   __ masm()->Assert(eq, AbortReason::kUnexpectedStackPointer, kScratchReg,
                     Operand(fp));
 }
@@ -79,4 +79,4 @@ void BaselineCompiler::VerifyFrameSize() {
 }  // namespace internal
 }  // namespace v8
 
-#endif  // V8_BASELINE_RISCV64_BASELINE_COMPILER_RISCV64_INL_H_
+#endif  // V8_BASELINE_RISCV_BASELINE_COMPILER_RISCV_INL_H_

src/builtins/builtins-sharedarraybuffer-gen.cc

@@ -251,7 +251,7 @@ TF_BUILTIN(AtomicsLoad, SharedArrayBufferBuiltinsAssembler) {
   BIND(&u32);
   Return(ChangeUint32ToTagged(AtomicLoad<Uint32T>(
       AtomicMemoryOrder::kSeqCst, backing_store, WordShl(index_word, 2))));
-#if V8_TARGET_ARCH_MIPS && !_MIPS_ARCH_MIPS32R6
+#if (V8_TARGET_ARCH_MIPS && !_MIPS_ARCH_MIPS32R6) || V8_TARGET_ARCH_RISCV32
   BIND(&i64);
   Goto(&u64);
 
@@ -268,7 +268,8 @@ TF_BUILTIN(AtomicsLoad, SharedArrayBufferBuiltinsAssembler) {
   BIND(&u64);
   Return(BigIntFromUnsigned64(AtomicLoad64<AtomicUint64>(
       AtomicMemoryOrder::kSeqCst, backing_store, WordShl(index_word, 3))));
-#endif
+#endif  //(V8_TARGET_ARCH_MIPS && !_MIPS_ARCH_MIPS32R6) ||
+        // V8_TARGET_ARCH_RISCV32
 
   // This shouldn't happen, we've already validated the type.
   BIND(&other);
@@ -523,8 +524,7 @@ TF_BUILTIN(AtomicsExchange, SharedArrayBufferBuiltinsAssembler) {
   // This shouldn't happen, we've already validated the type.
   BIND(&other);
   Unreachable();
-#endif  // V8_TARGET_ARCH_MIPS || V8_TARGET_ARCH_MIPS64 ||
-        // V8_TARGET_ARCH_RISCV64
+#endif  // V8_TARGET_ARCH_MIPS || V8_TARGET_ARCH_MIPS64
 
   BIND(&detached_or_out_of_bounds);
   {

src/codegen/assembler-arch.h

@@ -25,8 +25,8 @@
 #include "src/codegen/loong64/assembler-loong64.h"
 #elif V8_TARGET_ARCH_S390
 #include "src/codegen/s390/assembler-s390.h"
-#elif V8_TARGET_ARCH_RISCV64
-#include "src/codegen/riscv64/assembler-riscv64.h"
+#elif V8_TARGET_ARCH_RISCV32 || V8_TARGET_ARCH_RISCV64
+#include "src/codegen/riscv/assembler-riscv.h"
 #else
 #error Unknown architecture.
 #endif

src/codegen/assembler-inl.h

@@ -25,8 +25,8 @@
 #include "src/codegen/loong64/assembler-loong64-inl.h"
 #elif V8_TARGET_ARCH_S390
 #include "src/codegen/s390/assembler-s390-inl.h"
-#elif V8_TARGET_ARCH_RISCV64
-#include "src/codegen/riscv64/assembler-riscv64-inl.h"
+#elif V8_TARGET_ARCH_RISCV32 || V8_TARGET_ARCH_RISCV64
+#include "src/codegen/riscv/assembler-riscv-inl.h"
 #else
 #error Unknown architecture.
 #endif

src/codegen/constant-pool.cc

@@ -459,7 +459,7 @@ void ConstantPool::MaybeCheck() {
 
 #endif  // defined(V8_TARGET_ARCH_ARM64)
 
-#if defined(V8_TARGET_ARCH_RISCV64)
+#if defined(V8_TARGET_ARCH_RISCV64) || defined(V8_TARGET_ARCH_RISCV32)
 
 // Constant Pool.
 
@@ -706,7 +706,7 @@ void ConstantPool::MaybeCheck() {
   }
 }
 
-#endif  // defined(V8_TARGET_ARCH_RISCV64)
+#endif  // defined(V8_TARGET_ARCH_RISCV64) || defined(V8_TARGET_ARCH_RISCV32)
 
 }  // namespace internal
 }  // namespace v8

src/codegen/constant-pool.h

@@ -163,7 +163,8 @@ class ConstantPoolBuilder {
 
 #endif  // defined(V8_TARGET_ARCH_PPC) || defined(V8_TARGET_ARCH_PPC64)
 
-#if defined(V8_TARGET_ARCH_ARM64) || defined(V8_TARGET_ARCH_RISCV64)
+#if defined(V8_TARGET_ARCH_ARM64) || defined(V8_TARGET_ARCH_RISCV64) || \
+    defined(V8_TARGET_ARCH_RISCV32)
 
 class ConstantPoolKey {
  public:
@@ -345,7 +346,8 @@ class ConstantPool {
   int blocked_nesting_ = 0;
 };
 
-#endif  // defined(V8_TARGET_ARCH_ARM64)
+#endif  // defined(V8_TARGET_ARCH_ARM64) || defined(V8_TARGET_ARCH_RISCV64) ||
+        // defined(V8_TARGET_ARCH_RISCV32)
 
 }  // namespace internal
 }  // namespace v8

src/codegen/constants-arch.h

@@ -23,8 +23,8 @@
 #include "src/codegen/s390/constants-s390.h"
 #elif V8_TARGET_ARCH_X64
 #include "src/codegen/x64/constants-x64.h"
-#elif V8_TARGET_ARCH_RISCV64
-#include "src/codegen/riscv64/constants-riscv64.h"
+#elif V8_TARGET_ARCH_RISCV32 || V8_TARGET_ARCH_RISCV64
+#include "src/codegen/riscv/constants-riscv.h"
 #else
 #error Unsupported target architecture.
 #endif

src/codegen/cpu-features.h

@@ -76,6 +76,10 @@ enum CpuFeature {
   FPU,
   FP64FPU,
   RISCV_SIMD,
+#elif V8_TARGET_ARCH_RISCV32
+  FPU,
+  FP64FPU,
+  RISCV_SIMD,
 #endif
 
   NUMBER_OF_CPU_FEATURES

src/codegen/external-reference.cc

@@ -757,7 +757,7 @@ ExternalReference ExternalReference::invoke_accessor_getter_callback() {
 #define re_stack_check_func RegExpMacroAssemblerLOONG64::CheckStackGuardState
 #elif V8_TARGET_ARCH_S390
 #define re_stack_check_func RegExpMacroAssemblerS390::CheckStackGuardState
-#elif V8_TARGET_ARCH_RISCV64
+#elif V8_TARGET_ARCH_RISCV32 || V8_TARGET_ARCH_RISCV64
 #define re_stack_check_func RegExpMacroAssemblerRISCV::CheckStackGuardState
 #else
 UNREACHABLE();

src/codegen/interface-descriptors-inl.h

@@ -29,8 +29,8 @@
 #include "src/codegen/mips/interface-descriptors-mips-inl.h"
 #elif V8_TARGET_ARCH_LOONG64
 #include "src/codegen/loong64/interface-descriptors-loong64-inl.h"
-#elif V8_TARGET_ARCH_RISCV64
-#include "src/codegen/riscv64/interface-descriptors-riscv64-inl.h"
+#elif V8_TARGET_ARCH_RISCV32 || V8_TARGET_ARCH_RISCV64
+#include "src/codegen/riscv/interface-descriptors-riscv-inl.h"
 #else
 #error Unsupported target architecture.
 #endif
@@ -336,7 +336,7 @@ constexpr auto BaselineOutOfLinePrologueDescriptor::registers() {
 #if V8_TARGET_ARCH_X64 || V8_TARGET_ARCH_ARM64 || V8_TARGET_ARCH_ARM ||       \
     V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64 || V8_TARGET_ARCH_S390 ||      \
     V8_TARGET_ARCH_RISCV64 || V8_TARGET_ARCH_MIPS64 || V8_TARGET_ARCH_MIPS || \
-    V8_TARGET_ARCH_LOONG64
+    V8_TARGET_ARCH_LOONG64 || V8_TARGET_ARCH_RISCV32
   return RegisterArray(
       kContextRegister, kJSFunctionRegister, kJavaScriptCallArgCountRegister,
       kJavaScriptCallExtraArg1Register, kJavaScriptCallNewTargetRegister,
@@ -357,7 +357,7 @@ constexpr auto BaselineLeaveFrameDescriptor::registers() {
 #if V8_TARGET_ARCH_IA32 || V8_TARGET_ARCH_X64 || V8_TARGET_ARCH_ARM64 ||      \
     V8_TARGET_ARCH_ARM || V8_TARGET_ARCH_PPC || V8_TARGET_ARCH_PPC64 ||       \
     V8_TARGET_ARCH_S390 || V8_TARGET_ARCH_RISCV64 || V8_TARGET_ARCH_MIPS64 || \
-    V8_TARGET_ARCH_MIPS || V8_TARGET_ARCH_LOONG64
+    V8_TARGET_ARCH_MIPS || V8_TARGET_ARCH_LOONG64 || V8_TARGET_ARCH_RISCV32
   return RegisterArray(ParamsSizeRegister(), WeightRegister());
 #else
   return DefaultRegisterArray();

src/codegen/macro-assembler.h

@@ -63,9 +63,9 @@ enum class SmiCheck { kOmit, kInline };
 #elif V8_TARGET_ARCH_S390
 #include "src/codegen/s390/constants-s390.h"
 #include "src/codegen/s390/macro-assembler-s390.h"
-#elif V8_TARGET_ARCH_RISCV64
-#include "src/codegen/riscv64/constants-riscv64.h"
-#include "src/codegen/riscv64/macro-assembler-riscv64.h"
+#elif V8_TARGET_ARCH_RISCV32 || V8_TARGET_ARCH_RISCV64
+#include "src/codegen/riscv/constants-riscv.h"
+#include "src/codegen/riscv/macro-assembler-riscv.h"
 #else
 #error Unsupported target architecture.
 #endif

src/codegen/register-arch.h

@@ -25,8 +25,8 @@
 #include "src/codegen/loong64/register-loong64.h"
 #elif V8_TARGET_ARCH_S390
 #include "src/codegen/s390/register-s390.h"
-#elif V8_TARGET_ARCH_RISCV64
-#include "src/codegen/riscv64/register-riscv64.h"
+#elif V8_TARGET_ARCH_RISCV32 || V8_TARGET_ARCH_RISCV64
+#include "src/codegen/riscv/register-riscv.h"
 #else
 #error Unknown architecture.
 #endif

src/codegen/register-configuration.cc

@@ -19,7 +19,7 @@ static const int kMaxAllocatableGeneralRegisterCount =
     ALLOCATABLE_GENERAL_REGISTERS(REGISTER_COUNT) 0;
 static const int kMaxAllocatableDoubleRegisterCount =
     ALLOCATABLE_DOUBLE_REGISTERS(REGISTER_COUNT) 0;
-#if V8_TARGET_ARCH_RISCV64 || V8_TARGET_ARCH_PPC64
+#if V8_TARGET_ARCH_RISCV32 || V8_TARGET_ARCH_RISCV64 || V8_TARGET_ARCH_PPC64
 static const int kMaxAllocatableSIMD128RegisterCount =
     ALLOCATABLE_SIMD128_REGISTERS(REGISTER_COUNT) 0;
 #endif
@@ -38,16 +38,17 @@ static const int kAllocatableNoVFP32DoubleCodes[] = {
 #endif  // V8_TARGET_ARCH_ARM
 #undef REGISTER_CODE
 
-#if V8_TARGET_ARCH_RISCV64 || V8_TARGET_ARCH_PPC64
+#if V8_TARGET_ARCH_RISCV32 || V8_TARGET_ARCH_RISCV64 || V8_TARGET_ARCH_PPC64
 static const int kAllocatableSIMD128Codes[] = {
-#if V8_TARGET_ARCH_RISCV64
+#if V8_TARGET_ARCH_RISCV64 || V8_TARGET_ARCH_RISCV32
 #define REGISTER_CODE(R) kVRCode_##R,
 #else
 #define REGISTER_CODE(R) kSimd128Code_##R,
 #endif
     ALLOCATABLE_SIMD128_REGISTERS(REGISTER_CODE)};
 #undef REGISTER_CODE
-#endif  // V8_TARGET_ARCH_RISCV64 || V8_TARGET_ARCH_PPC64
+#endif  // V8_TARGET_ARCH_RISCV32 || V8_TARGET_ARCH_RISCV64 ||
+        // V8_TARGET_ARCH_PPC64
 
 static_assert(RegisterConfiguration::kMaxGeneralRegisters >=
               Register::kNumRegisters);
@@ -95,6 +96,8 @@ static int get_num_allocatable_double_registers() {
       kMaxAllocatableDoubleRegisterCount;
 #elif V8_TARGET_ARCH_RISCV64
       kMaxAllocatableDoubleRegisterCount;
+#elif V8_TARGET_ARCH_RISCV32
+      kMaxAllocatableDoubleRegisterCount;
 #else
 #error Unsupported target architecture.
 #endif
@@ -104,7 +107,7 @@ static int get_num_allocatable_double_registers() {
 
 static int get_num_allocatable_simd128_registers() {
   return
-#if V8_TARGET_ARCH_RISCV64 || V8_TARGET_ARCH_PPC64
+#if V8_TARGET_ARCH_RISCV32 || V8_TARGET_ARCH_RISCV64 || V8_TARGET_ARCH_PPC64
       kMaxAllocatableSIMD128RegisterCount;
 #else
       0;
@@ -125,7 +128,7 @@ static const int* get_allocatable_double_codes() {
 
 static const int* get_allocatable_simd128_codes() {
   return
-#if V8_TARGET_ARCH_RISCV64 || V8_TARGET_ARCH_PPC64
+#if V8_TARGET_ARCH_RISCV32 || V8_TARGET_ARCH_RISCV64 || V8_TARGET_ARCH_PPC64
       kAllocatableSIMD128Codes;
 #else
       kAllocatableDoubleCodes;

src/codegen/reglist.h

@@ -23,8 +23,8 @@
 #include "src/codegen/loong64/reglist-loong64.h"
 #elif V8_TARGET_ARCH_S390
 #include "src/codegen/s390/reglist-s390.h"
-#elif V8_TARGET_ARCH_RISCV64
-#include "src/codegen/riscv64/reglist-riscv64.h"
+#elif V8_TARGET_ARCH_RISCV32 || V8_TARGET_ARCH_RISCV64
+#include "src/codegen/riscv/reglist-riscv.h"
 #else
 #error Unknown architecture.
 #endif

src/codegen/reloc-info.cc

@@ -309,10 +309,11 @@ bool RelocInfo::OffHeapTargetIsCodedSpecially() {
 #if defined(V8_TARGET_ARCH_ARM) || defined(V8_TARGET_ARCH_ARM64) || \
     defined(V8_TARGET_ARCH_X64)
   return false;
-#elif defined(V8_TARGET_ARCH_IA32) || defined(V8_TARGET_ARCH_MIPS) || \
-    defined(V8_TARGET_ARCH_MIPS64) || defined(V8_TARGET_ARCH_PPC) ||  \
-    defined(V8_TARGET_ARCH_PPC64) || defined(V8_TARGET_ARCH_S390) ||  \
-    defined(V8_TARGET_ARCH_RISCV64) || defined(V8_TARGET_ARCH_LOONG64)
+#elif defined(V8_TARGET_ARCH_IA32) || defined(V8_TARGET_ARCH_MIPS) ||     \
+    defined(V8_TARGET_ARCH_MIPS64) || defined(V8_TARGET_ARCH_PPC) ||      \
+    defined(V8_TARGET_ARCH_PPC64) || defined(V8_TARGET_ARCH_S390) ||      \
+    defined(V8_TARGET_ARCH_RISCV64) || defined(V8_TARGET_ARCH_LOONG64) || \
+    defined(V8_TARGET_ARCH_RISCV32)
   return true;
 #endif
 }

src/codegen/reloc-info.h

@@ -72,7 +72,8 @@ class RelocInfo {
     EXTERNAL_REFERENCE,  // The address of an external C++ function.
     INTERNAL_REFERENCE,  // An address inside the same function.
 
-    // Encoded internal reference, used only on RISCV64, MIPS, MIPS64 and PPC.
+    // Encoded internal reference, used only on RISCV64, RISCV32, MIPS, MIPS64
+    // and PPC.
     INTERNAL_REFERENCE_ENCODED,
 
     // An off-heap instruction stream target. See http://goo.gl/Z2HUiM.

src/codegen/riscv64/assembler-riscv64-inl.h → src/codegen/riscv/assembler-riscv-inl.h

@@ -32,11 +32,11 @@
 // modified significantly by Google Inc.
 // Copyright 2021 the V8 project authors. All rights reserved.
 
-#ifndef V8_CODEGEN_RISCV64_ASSEMBLER_RISCV64_INL_H_
-#define V8_CODEGEN_RISCV64_ASSEMBLER_RISCV64_INL_H_
+#ifndef V8_CODEGEN_RISCV_ASSEMBLER_RISCV_INL_H_
+#define V8_CODEGEN_RISCV_ASSEMBLER_RISCV_INL_H_
 
+#include "src/codegen/assembler-arch.h"
 #include "src/codegen/assembler.h"
-#include "src/codegen/riscv64/assembler-riscv64.h"
 #include "src/debug/debug.h"
 #include "src/objects/objects-inl.h"
 
@@ -45,15 +45,10 @@ namespace internal {
 
 bool CpuFeatures::SupportsOptimizer() { return IsSupported(FPU); }
 
-// -----------------------------------------------------------------------------
-// Operand and MemOperand.
-
-bool Operand::is_reg() const { return rm_.is_valid(); }
-
-int64_t Operand::immediate() const {
-  DCHECK(!is_reg());
-  DCHECK(!IsHeapObjectRequest());
-  return value_.immediate;
+void Assembler::CheckBuffer() {
+  if (buffer_space() <= kGap) {
+    GrowBuffer();
+  }
 }
 
 // -----------------------------------------------------------------------------
@@ -91,7 +86,11 @@ Address RelocInfo::target_address_address() {
   // place, ready to be patched with the target. After jump optimization,
   // that is the address of the instruction that follows J/JAL/JR/JALR
   // instruction.
+#ifdef V8_TARGET_ARCH_RISCV64
   return pc_ + Assembler::kInstructionsFor64BitConstant * kInstrSize;
+#elif defined(V8_TARGET_ARCH_RISCV32)
+  return pc_ + Assembler::kInstructionsFor32BitConstant * kInstrSize;
+#endif
 }
 
 Address RelocInfo::constant_pool_entry_address() { UNREACHABLE(); }
@@ -142,7 +141,11 @@ int Assembler::deserialization_special_target_size(
 
 void Assembler::set_target_internal_reference_encoded_at(Address pc,
                                                          Address target) {
+#ifdef V8_TARGET_ARCH_RISCV64
   set_target_value_at(pc, static_cast<uint64_t>(target));
+#elif defined(V8_TARGET_ARCH_RISCV32)
+  set_target_value_at(pc, static_cast<uint32_t>(target));
+#endif
 }
 
 void Assembler::deserialization_set_target_internal_reference_at(
@@ -279,49 +282,9 @@ void RelocInfo::WipeOut() {
   }
 }
 
-// -----------------------------------------------------------------------------
-// Assembler.
-
-void Assembler::CheckBuffer() {
-  if (buffer_space() <= kGap) {
-    GrowBuffer();
-  }
-}
-
-template <typename T>
-void Assembler::EmitHelper(T x) {
-  *reinterpret_cast<T*>(pc_) = x;
-  pc_ += sizeof(x);
-}
-
-void Assembler::emit(Instr x) {
-  if (!is_buffer_growth_blocked()) {
-    CheckBuffer();
-  }
-  DEBUG_PRINTF("%p: ", pc_);
-  disassembleInstr(x);
-  EmitHelper(x);
-  CheckTrampolinePoolQuick();
-}
-
-void Assembler::emit(ShortInstr x) {
-  if (!is_buffer_growth_blocked()) {
-    CheckBuffer();
-  }
-  DEBUG_PRINTF("%p: ", pc_);
-  disassembleInstr(x);
-  EmitHelper(x);
-  CheckTrampolinePoolQuick();
-}
-
-void Assembler::emit(uint64_t data) {
-  if (!is_buffer_growth_blocked()) CheckBuffer();
-  EmitHelper(data);
-}
-
 EnsureSpace::EnsureSpace(Assembler* assembler) { assembler->CheckBuffer(); }
 
 }  // namespace internal
 }  // namespace v8
 
-#endif  // V8_CODEGEN_RISCV64_ASSEMBLER_RISCV64_INL_H_
+#endif  // V8_CODEGEN_RISCV_ASSEMBLER_RISCV_INL_H_

src/codegen/riscv/base-assembler-riscv.h

+// Copyright (c) 1994-2006 Sun Microsystems Inc.
+// All Rights Reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+// - Redistributions of source code must retain the above copyright notice,
+// this list of conditions and the following disclaimer.
+//
+// - Redistribution in binary form must reproduce the above copyright
+// notice, this list of conditions and the following disclaimer in the
+// documentation and/or other materials provided with the distribution.
+//
+// - Neither the name of Sun Microsystems or the names of contributors may
+// be used to endorse or promote products derived from this software without
+// specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+// IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+// THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+// PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// The original source code covered by the above license above has been
+// modified significantly by Google Inc.
+// Copyright 2021 the V8 project authors. All rights reserved.
+
+#ifndef V8_CODEGEN_RISCV_BASE_ASSEMBLER_RISCV_H_
+#define V8_CODEGEN_RISCV_BASE_ASSEMBLER_RISCV_H_
+
+#include <stdio.h>
+
+#include <memory>
+#include <set>
+
+#include "src/codegen/assembler.h"
+#include "src/codegen/constant-pool.h"
+#include "src/codegen/external-reference.h"
+#include "src/codegen/label.h"
+#include "src/codegen/riscv/constants-riscv.h"
+#include "src/codegen/riscv/register-riscv.h"
+#include "src/objects/contexts.h"
+#include "src/objects/smi.h"
+
+namespace v8 {
+namespace internal {
+
+#define DEBUG_PRINTF(...) \
+  if (FLAG_riscv_debug) { \
+    printf(__VA_ARGS__);  \
+  }
+
+class SafepointTableBuilder;
+
+class AssemblerRiscvBase {
+ protected:
+  // Returns the branch offset to the given label from the current code
+  // position. Links the label to the current position if it is still unbound.
+  // Manages the jump elimination optimization if the second parameter is true.
+  enum OffsetSize : int {
+    kOffset21 = 21,  // RISCV jal
+    kOffset12 = 12,  // RISCV imm12
+    kOffset20 = 20,  // RISCV imm20
+    kOffset13 = 13,  // RISCV branch
+    kOffset32 = 32,  // RISCV auipc + instr_I
+    kOffset11 = 11,  // RISCV C_J
+    kOffset9 = 9     // RISCV compressed branch
+  };
+  virtual int32_t branch_offset_helper(Label* L, OffsetSize bits) = 0;
+
+  virtual void emit(Instr x) = 0;
+  virtual void emit(ShortInstr x) = 0;
+  virtual void emit(uint64_t x) = 0;
+  // Instruction generation.
+
+  // ----- Top-level instruction formats match those in the ISA manual
+  // (R, I, S, B, U, J). These match the formats defined in LLVM's
+  // RISCVInstrFormats.td.
+  void GenInstrR(uint8_t funct7, uint8_t funct3, BaseOpcode opcode, Register rd,
+                 Register rs1, Register rs2);
+  void GenInstrR(uint8_t funct7, uint8_t funct3, BaseOpcode opcode,
+                 FPURegister rd, FPURegister rs1, FPURegister rs2);
+  void GenInstrR(uint8_t funct7, uint8_t funct3, BaseOpcode opcode, Register rd,
+                 FPURegister rs1, Register rs2);
+  void GenInstrR(uint8_t funct7, uint8_t funct3, BaseOpcode opcode,
+                 FPURegister rd, Register rs1, Register rs2);
+  void GenInstrR(uint8_t funct7, uint8_t funct3, BaseOpcode opcode,
+                 FPURegister rd, FPURegister rs1, Register rs2);
+  void GenInstrR(uint8_t funct7, uint8_t funct3, BaseOpcode opcode, Register rd,
+                 FPURegister rs1, FPURegister rs2);
+  void GenInstrR4(uint8_t funct2, BaseOpcode opcode, Register rd, Register rs1,
+                  Register rs2, Register rs3, FPURoundingMode frm);
+  void GenInstrR4(uint8_t funct2, BaseOpcode opcode, FPURegister rd,
+                  FPURegister rs1, FPURegister rs2, FPURegister rs3,
+                  FPURoundingMode frm);
+  void GenInstrRAtomic(uint8_t funct5, bool aq, bool rl, uint8_t funct3,
+                       Register rd, Register rs1, Register rs2);
+  void GenInstrRFrm(uint8_t funct7, BaseOpcode opcode, Register rd,
+                    Register rs1, Register rs2, FPURoundingMode frm);
+  void GenInstrI(uint8_t funct3, BaseOpcode opcode, Register rd, Register rs1,
+                 int16_t imm12);
+  void GenInstrI(uint8_t funct3, BaseOpcode opcode, FPURegister rd,
+                 Register rs1, int16_t imm12);
+  void GenInstrIShift(bool arithshift, uint8_t funct3, BaseOpcode opcode,
+                      Register rd, Register rs1, uint8_t shamt);
+  void GenInstrIShiftW(bool arithshift, uint8_t funct3, BaseOpcode opcode,
+                       Register rd, Register rs1, uint8_t shamt);
+  void GenInstrS(uint8_t funct3, BaseOpcode opcode, Register rs1, Register rs2,
+                 int16_t imm12);
+  void GenInstrS(uint8_t funct3, BaseOpcode opcode, Register rs1,
+                 FPURegister rs2, int16_t imm12);
+  void GenInstrB(uint8_t funct3, BaseOpcode opcode, Register rs1, Register rs2,
+                 int16_t imm12);
+  void GenInstrU(BaseOpcode opcode, Register rd, int32_t imm20);
+  void GenInstrJ(BaseOpcode opcode, Register rd, int32_t imm20);
+  void GenInstrCR(uint8_t funct4, BaseOpcode opcode, Register rd, Register rs2);
+  void GenInstrCA(uint8_t funct6, BaseOpcode opcode, Register rd, uint8_t funct,
+                  Register rs2);
+  void GenInstrCI(uint8_t funct3, BaseOpcode opcode, Register rd, int8_t imm6);
+  void GenInstrCIU(uint8_t funct3, BaseOpcode opcode, Register rd,
+                   uint8_t uimm6);
+  void GenInstrCIU(uint8_t funct3, BaseOpcode opcode, FPURegister rd,
+                   uint8_t uimm6);
+  void GenInstrCIW(uint8_t funct3, BaseOpcode opcode, Register rd,
+                   uint8_t uimm8);
+  void GenInstrCSS(uint8_t funct3, BaseOpcode opcode, FPURegister rs2,
+                   uint8_t uimm6);
+  void GenInstrCSS(uint8_t funct3, BaseOpcode opcode, Register rs2,
+                   uint8_t uimm6);
+  void GenInstrCL(uint8_t funct3, BaseOpcode opcode, Register rd, Register rs1,
+                  uint8_t uimm5);
+  void GenInstrCL(uint8_t funct3, BaseOpcode opcode, FPURegister rd,
+                  Register rs1, uint8_t uimm5);
+  void GenInstrCS(uint8_t funct3, BaseOpcode opcode, Register rs2, Register rs1,
+                  uint8_t uimm5);
+  void GenInstrCS(uint8_t funct3, BaseOpcode opcode, FPURegister rs2,
+                  Register rs1, uint8_t uimm5);
+  void GenInstrCJ(uint8_t funct3, BaseOpcode opcode, uint16_t uint11);
+  void GenInstrCB(uint8_t funct3, BaseOpcode opcode, Register rs1,
+                  uint8_t uimm8);
+  void GenInstrCBA(uint8_t funct3, uint8_t funct2, BaseOpcode opcode,
+                   Register rs1, int8_t imm6);
+
+  // ----- Instruction class templates match those in LLVM's RISCVInstrInfo.td
+  void GenInstrBranchCC_rri(uint8_t funct3, Register rs1, Register rs2,
+                            int16_t imm12);
+  void GenInstrLoad_ri(uint8_t funct3, Register rd, Register rs1,
+                       int16_t imm12);
+  void GenInstrStore_rri(uint8_t funct3, Register rs1, Register rs2,
+                         int16_t imm12);
+  void GenInstrALU_ri(uint8_t funct3, Register rd, Register rs1, int16_t imm12);
+  void GenInstrShift_ri(bool arithshift, uint8_t funct3, Register rd,
+                        Register rs1, uint8_t shamt);
+  void GenInstrALU_rr(uint8_t funct7, uint8_t funct3, Register rd, Register rs1,
+                      Register rs2);
+  void GenInstrCSR_ir(uint8_t funct3, Register rd, ControlStatusReg csr,
+                      Register rs1);
+  void GenInstrCSR_ii(uint8_t funct3, Register rd, ControlStatusReg csr,
+                      uint8_t rs1);
+  void GenInstrShiftW_ri(bool arithshift, uint8_t funct3, Register rd,
+                         Register rs1, uint8_t shamt);
+  void GenInstrALUW_rr(uint8_t funct7, uint8_t funct3, Register rd,
+                       Register rs1, Register rs2);
+  void GenInstrPriv(uint8_t funct7, Register rs1, Register rs2);
+  void GenInstrLoadFP_ri(uint8_t funct3, FPURegister rd, Register rs1,
+                         int16_t imm12);
+  void GenInstrStoreFP_rri(uint8_t funct3, Register rs1, FPURegister rs2,
+                           int16_t imm12);
+  void GenInstrALUFP_rr(uint8_t funct7, uint8_t funct3, FPURegister rd,
+                        FPURegister rs1, FPURegister rs2);
+  void GenInstrALUFP_rr(uint8_t funct7, uint8_t funct3, FPURegister rd,
+                        Register rs1, Register rs2);
+  void GenInstrALUFP_rr(uint8_t funct7, uint8_t funct3, FPURegister rd,
+                        FPURegister rs1, Register rs2);
+  void GenInstrALUFP_rr(uint8_t funct7, uint8_t funct3, Register rd,
+                        FPURegister rs1, Register rs2);
+  void GenInstrALUFP_rr(uint8_t funct7, uint8_t funct3, Register rd,
+                        FPURegister rs1, FPURegister rs2);
+  virtual void BlockTrampolinePoolFor(int instructions) = 0;
+};
+
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_CODEGEN_RISCV_BASE_ASSEMBLER_RISCV_H_

src/codegen/riscv64/constants-riscv64.cc → src/codegen/riscv/base-constants-riscv.cc

 // Copyright 2021 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
-
-#if V8_TARGET_ARCH_RISCV64
-
-#include "src/codegen/riscv64/constants-riscv64.h"
+#include "src/codegen/riscv/constants-riscv.h"
+#include "src/execution/simulator.h"
 
 namespace v8 {
 namespace internal {
@@ -144,6 +142,95 @@ int VRegisters::Number(const char* name) {
   return kInvalidVRegister;
 }
 
+bool InstructionBase::IsShortInstruction() const {
+  uint8_t FirstByte = *reinterpret_cast<const uint8_t*>(this);
+  return (FirstByte & 0x03) <= C2;
+}
+
+template <class T>
+int InstructionGetters<T>::RvcRdValue() const {
+  DCHECK(this->IsShortInstruction());
+  return this->Bits(kRvcRdShift + kRvcRdBits - 1, kRvcRdShift);
+}
+
+template <class T>
+int InstructionGetters<T>::RvcRs2Value() const {
+  DCHECK(this->IsShortInstruction());
+  return this->Bits(kRvcRs2Shift + kRvcRs2Bits - 1, kRvcRs2Shift);
+}
+
+template <class T>
+int InstructionGetters<T>::RvcRs1sValue() const {
+  DCHECK(this->IsShortInstruction());
+  return 0b1000 + this->Bits(kRvcRs1sShift + kRvcRs1sBits - 1, kRvcRs1sShift);
+}
+
+template <class T>
+int InstructionGetters<T>::RvcRs2sValue() const {
+  DCHECK(this->IsShortInstruction());
+  return 0b1000 + this->Bits(kRvcRs2sShift + kRvcRs2sBits - 1, kRvcRs2sShift);
+}
+
+template <class T>
+inline int InstructionGetters<T>::RvcFunct6Value() const {
+  DCHECK(this->IsShortInstruction());
+  return this->Bits(kRvcFunct6Shift + kRvcFunct6Bits - 1, kRvcFunct6Shift);
+}
+
+template <class T>
+inline int InstructionGetters<T>::RvcFunct4Value() const {
+  DCHECK(this->IsShortInstruction());
+  return this->Bits(kRvcFunct4Shift + kRvcFunct4Bits - 1, kRvcFunct4Shift);
+}
+
+template <class T>
+inline int InstructionGetters<T>::RvcFunct3Value() const {
+  DCHECK(this->IsShortInstruction());
+  return this->Bits(kRvcFunct3Shift + kRvcFunct3Bits - 1, kRvcFunct3Shift);
+}
+
+template <class T>
+inline int InstructionGetters<T>::RvcFunct2Value() const {
+  DCHECK(this->IsShortInstruction());
+  return this->Bits(kRvcFunct2Shift + kRvcFunct2Bits - 1, kRvcFunct2Shift);
+}
+
+template <class T>
+inline int InstructionGetters<T>::RvcFunct2BValue() const {
+  DCHECK(this->IsShortInstruction());
+  return this->Bits(kRvcFunct2BShift + kRvcFunct2Bits - 1, kRvcFunct2BShift);
+}
+
+template <class T>
+uint32_t InstructionGetters<T>::Rvvzimm() const {
+  if ((this->InstructionBits() &
+       (kBaseOpcodeMask | kFunct3Mask | 0x80000000)) == RO_V_VSETVLI) {
+    uint32_t Bits = this->InstructionBits();
+    uint32_t zimm = Bits & kRvvZimmMask;
+    return zimm >> kRvvZimmShift;
+  } else {
+    DCHECK_EQ(
+        this->InstructionBits() & (kBaseOpcodeMask | kFunct3Mask | 0xC0000000),
+        RO_V_VSETIVLI);
+    uint32_t Bits = this->InstructionBits();
+    uint32_t zimm = Bits & kRvvZimmMask;
+    return (zimm >> kRvvZimmShift) & 0x3FF;
+  }
+}
+
+template <class T>
+uint32_t InstructionGetters<T>::Rvvuimm() const {
+  DCHECK_EQ(
+      this->InstructionBits() & (kBaseOpcodeMask | kFunct3Mask | 0xC0000000),
+      RO_V_VSETIVLI);
+  uint32_t Bits = this->InstructionBits();
+  uint32_t uimm = Bits & kRvvUimmMask;
+  return uimm >> kRvvUimmShift;
+}
+
+template class InstructionGetters<InstructionBase>;
+template class InstructionGetters<SimInstructionBase>;
+
 InstructionBase::Type InstructionBase::InstructionType() const {
   if (IsIllegalInstruction()) {
     return kUnsupported;
@@ -155,15 +242,21 @@ InstructionBase::Type InstructionBase::InstructionType() const {
         return kCIWType;
       case RO_C_FLD:
       case RO_C_LW:
+#ifdef V8_TARGET_ARCH_RISCV64
       case RO_C_LD:
+#endif
         return kCLType;
       case RO_C_FSD:
       case RO_C_SW:
+#ifdef V8_TARGET_ARCH_RISCV64
       case RO_C_SD:
+#endif
         return kCSType;
       case RO_C_NOP_ADDI:
-      case RO_C_ADDIW:
       case RO_C_LI:
+#ifdef V8_TARGET_ARCH_RISCV64
+      case RO_C_ADDIW:
+#endif
       case RO_C_LUI_ADD:
         return kCIType;
       case RO_C_MISC_ALU:
@@ -179,13 +272,17 @@ InstructionBase::Type InstructionBase::InstructionType() const {
       case RO_C_SLLI:
       case RO_C_FLDSP:
       case RO_C_LWSP:
+#ifdef V8_TARGET_ARCH_RISCV64
       case RO_C_LDSP:
+#endif
         return kCIType;
       case RO_C_JR_MV_ADD:
         return kCRType;
       case RO_C_FSDSP:
       case RO_C_SWSP:
+#ifdef V8_TARGET_ARCH_RISCV64
       case RO_C_SDSP:
+#endif
         return kCSSType;
       default:
         break;
@@ -241,5 +338,3 @@ InstructionBase::Type InstructionBase::InstructionType() const {
 
 }  // namespace internal
 }  // namespace v8
-
-#endif  // V8_TARGET_ARCH_RISCV64

src/codegen/riscv/base-riscv-i.cc

+// Copyright 2022 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+#include "src/codegen/riscv/base-riscv-i.h"
+
+namespace v8 {
+namespace internal {
+
+void AssemblerRISCVI::lui(Register rd, int32_t imm20) {
+  GenInstrU(LUI, rd, imm20);
+}
+
+void AssemblerRISCVI::auipc(Register rd, int32_t imm20) {
+  GenInstrU(AUIPC, rd, imm20);
+}
+
+// Jumps
+
+void AssemblerRISCVI::jal(Register rd, int32_t imm21) {
+  GenInstrJ(JAL, rd, imm21);
+  BlockTrampolinePoolFor(1);
+}
+
+void AssemblerRISCVI::jalr(Register rd, Register rs1, int16_t imm12) {
+  GenInstrI(0b000, JALR, rd, rs1, imm12);
+  BlockTrampolinePoolFor(1);
+}
+
+// Branches
+
+void AssemblerRISCVI::beq(Register rs1, Register rs2, int16_t imm13) {
+  GenInstrBranchCC_rri(0b000, rs1, rs2, imm13);
+}
+
+void AssemblerRISCVI::bne(Register rs1, Register rs2, int16_t imm13) {
+  GenInstrBranchCC_rri(0b001, rs1, rs2, imm13);
+}
+
+void AssemblerRISCVI::blt(Register rs1, Register rs2, int16_t imm13) {
+  GenInstrBranchCC_rri(0b100, rs1, rs2, imm13);
+}
+
+void AssemblerRISCVI::bge(Register rs1, Register rs2, int16_t imm13) {
+  GenInstrBranchCC_rri(0b101, rs1, rs2, imm13);
+}
+
+void AssemblerRISCVI::bltu(Register rs1, Register rs2, int16_t imm13) {
+  GenInstrBranchCC_rri(0b110, rs1, rs2, imm13);
+}
+
+void AssemblerRISCVI::bgeu(Register rs1, Register rs2, int16_t imm13) {
+  GenInstrBranchCC_rri(0b111, rs1, rs2, imm13);
+}
+
+// Loads
+
+void AssemblerRISCVI::lb(Register rd, Register rs1, int16_t imm12) {
+  GenInstrLoad_ri(0b000, rd, rs1, imm12);
+}
+
+void AssemblerRISCVI::lh(Register rd, Register rs1, int16_t imm12) {
+  GenInstrLoad_ri(0b001, rd, rs1, imm12);
+}
+
+void AssemblerRISCVI::lw(Register rd, Register rs1, int16_t imm12) {
+  GenInstrLoad_ri(0b010, rd, rs1, imm12);
+}
+
+void AssemblerRISCVI::lbu(Register rd, Register rs1, int16_t imm12) {
+  GenInstrLoad_ri(0b100, rd, rs1, imm12);
+}
+
+void AssemblerRISCVI::lhu(Register rd, Register rs1, int16_t imm12) {
+  GenInstrLoad_ri(0b101, rd, rs1, imm12);
+}
+
+// Stores
+
+void AssemblerRISCVI::sb(Register source, Register base, int16_t imm12) {
+  GenInstrStore_rri(0b000, base, source, imm12);
+}
+
+void AssemblerRISCVI::sh(Register source, Register base, int16_t imm12) {
+  GenInstrStore_rri(0b001, base, source, imm12);
+}
+
+void AssemblerRISCVI::sw(Register source, Register base, int16_t imm12) {
+  GenInstrStore_rri(0b010, base, source, imm12);
+}
+
+// Arithmetic with immediate
+
+void AssemblerRISCVI::addi(Register rd, Register rs1, int16_t imm12) {
+  GenInstrALU_ri(0b000, rd, rs1, imm12);
+}
+
+void AssemblerRISCVI::slti(Register rd, Register rs1, int16_t imm12) {
+  GenInstrALU_ri(0b010, rd, rs1, imm12);
+}
+
+void AssemblerRISCVI::sltiu(Register rd, Register rs1, int16_t imm12) {
+  GenInstrALU_ri(0b011, rd, rs1, imm12);
+}
+
+void AssemblerRISCVI::xori(Register rd, Register rs1, int16_t imm12) {
+  GenInstrALU_ri(0b100, rd, rs1, imm12);
+}
+
+void AssemblerRISCVI::ori(Register rd, Register rs1, int16_t imm12) {
+  GenInstrALU_ri(0b110, rd, rs1, imm12);
+}
+
+void AssemblerRISCVI::andi(Register rd, Register rs1, int16_t imm12) {
+  GenInstrALU_ri(0b111, rd, rs1, imm12);
+}
+
+void AssemblerRISCVI::slli(Register rd, Register rs1, uint8_t shamt) {
+  GenInstrShift_ri(0, 0b001, rd, rs1, shamt & 0x3f);
+}
+
+void AssemblerRISCVI::srli(Register rd, Register rs1, uint8_t shamt) {
+  GenInstrShift_ri(0, 0b101, rd, rs1, shamt & 0x3f);
+}
+
+void AssemblerRISCVI::srai(Register rd, Register rs1, uint8_t shamt) {
+  GenInstrShift_ri(1, 0b101, rd, rs1, shamt & 0x3f);
+}
+
+// Arithmetic
+
+void AssemblerRISCVI::add(Register rd, Register rs1, Register rs2) {
+  GenInstrALU_rr(0b0000000, 0b000, rd, rs1, rs2);
+}
+
+void AssemblerRISCVI::sub(Register rd, Register rs1, Register rs2) {
+  GenInstrALU_rr(0b0100000, 0b000, rd, rs1, rs2);
+}
+
+void AssemblerRISCVI::sll(Register rd, Register rs1, Register rs2) {
+  GenInstrALU_rr(0b0000000, 0b001, rd, rs1, rs2);
+}
+
+void AssemblerRISCVI::slt(Register rd, Register rs1, Register rs2) {
+  GenInstrALU_rr(0b0000000, 0b010, rd, rs1, rs2);
+}
+
+void AssemblerRISCVI::sltu(Register rd, Register rs1, Register rs2) {
+  GenInstrALU_rr(0b0000000, 0b011, rd, rs1, rs2);
+}
+
+void AssemblerRISCVI::xor_(Register rd, Register rs1, Register rs2) {
+  GenInstrALU_rr(0b0000000, 0b100, rd, rs1, rs2);
+}
+
+void AssemblerRISCVI::srl(Register rd, Register rs1, Register rs2) {
+  GenInstrALU_rr(0b0000000, 0b101, rd, rs1, rs2);
+}
+
+void AssemblerRISCVI::sra(Register rd, Register rs1, Register rs2) {
+  GenInstrALU_rr(0b0100000, 0b101, rd, rs1, rs2);
+}
+
+void AssemblerRISCVI::or_(Register rd, Register rs1, Register rs2) {
+  GenInstrALU_rr(0b0000000, 0b110, rd, rs1, rs2);
+}
+
+void AssemblerRISCVI::and_(Register rd, Register rs1, Register rs2) {
+  GenInstrALU_rr(0b0000000, 0b111, rd, rs1, rs2);
+}
+
+// Memory fences
+
+void AssemblerRISCVI::fence(uint8_t pred, uint8_t succ) {
+  DCHECK(is_uint4(pred) && is_uint4(succ));
+  uint16_t imm12 = succ | (pred << 4) | (0b0000 << 8);
+  GenInstrI(0b000, MISC_MEM, ToRegister(0), ToRegister(0), imm12);
+}
+
+void AssemblerRISCVI::fence_tso() {
+  uint16_t imm12 = (0b0011) | (0b0011 << 4) | (0b1000 << 8);
+  GenInstrI(0b000, MISC_MEM, ToRegister(0), ToRegister(0), imm12);
+}
+
+// Environment call / break
+
+void AssemblerRISCVI::ecall() {
+  GenInstrI(0b000, SYSTEM, ToRegister(0), ToRegister(0), 0);
+}
+
+void AssemblerRISCVI::ebreak() {
+  GenInstrI(0b000, SYSTEM, ToRegister(0), ToRegister(0), 1);
+}
+
+// This is a de facto standard (as set by GNU binutils) 32-bit unimplemented
+// instruction (i.e., it should always trap, if your implementation has invalid
+// instruction traps).
+void AssemblerRISCVI::unimp() {
+  GenInstrI(0b001, SYSTEM, ToRegister(0), ToRegister(0), 0b110000000000);
+}
+
+bool AssemblerRISCVI::IsBranch(Instr instr) {
+  return (instr & kBaseOpcodeMask) == BRANCH;
+}
+
+bool AssemblerRISCVI::IsJump(Instr instr) {
+  int Op = instr & kBaseOpcodeMask;
+  return Op == JAL || Op == JALR;
+}
+
+bool AssemblerRISCVI::IsNop(Instr instr) { return instr == kNopByte; }
+
+bool AssemblerRISCVI::IsJal(Instr instr) {
+  return (instr & kBaseOpcodeMask) == JAL;
+}
+
+bool AssemblerRISCVI::IsJalr(Instr instr) {
+  return (instr & kBaseOpcodeMask) == JALR;
+}
+
+bool AssemblerRISCVI::IsLui(Instr instr) {
+  return (instr & kBaseOpcodeMask) == LUI;
+}
+bool AssemblerRISCVI::IsAuipc(Instr instr) {
+  return (instr & kBaseOpcodeMask) == AUIPC;
+}
+bool AssemblerRISCVI::IsAddi(Instr instr) {
+  return (instr & (kBaseOpcodeMask | kFunct3Mask)) == RO_ADDI;
+}
+bool AssemblerRISCVI::IsOri(Instr instr) {
+  return (instr & (kBaseOpcodeMask | kFunct3Mask)) == RO_ORI;
+}
+bool AssemblerRISCVI::IsSlli(Instr instr) {
+  return (instr & (kBaseOpcodeMask | kFunct3Mask)) == RO_SLLI;
+}
+
+int AssemblerRISCVI::JumpOffset(Instr instr) {
+  int32_t imm21 = ((instr & 0x7fe00000) >> 20) | ((instr & 0x100000) >> 9) |
+                  (instr & 0xff000) | ((instr & 0x80000000) >> 11);
+  imm21 = imm21 << 11 >> 11;
+  return imm21;
+}
+
+int AssemblerRISCVI::JalrOffset(Instr instr) {
+  DCHECK(IsJalr(instr));
+  int32_t imm12 = static_cast<int32_t>(instr & kImm12Mask) >> 20;
+  return imm12;
+}
+
+int AssemblerRISCVI::AuipcOffset(Instr instr) {
+  DCHECK(IsAuipc(instr));
+  int32_t imm20 = static_cast<int32_t>(instr & kImm20Mask);
+  return imm20;
+}
+
+bool AssemblerRISCVI::IsLw(Instr instr) {
+  return (instr & (kBaseOpcodeMask | kFunct3Mask)) == RO_LW;
+}
+
+int AssemblerRISCVI::LoadOffset(Instr instr) {
+#if V8_TARGET_ARCH_RISCV64
+  DCHECK(IsLd(instr));
+#elif V8_TARGET_ARCH_RISCV32
+  DCHECK(IsLw(instr));
+#endif
+  int32_t imm12 = static_cast<int32_t>(instr & kImm12Mask) >> 20;
+  return imm12;
+}
+
+#ifdef V8_TARGET_ARCH_RISCV64
+
+bool AssemblerRISCVI::IsAddiw(Instr instr) {
+  return (instr & (kBaseOpcodeMask | kFunct3Mask)) == RO_ADDIW;
+}
+
+bool AssemblerRISCVI::IsLd(Instr instr) {
+  return (instr & (kBaseOpcodeMask | kFunct3Mask)) == RO_LD;
+}
+
+void AssemblerRISCVI::lwu(Register rd, Register rs1, int16_t imm12) {
+  GenInstrLoad_ri(0b110, rd, rs1, imm12);
+}
+
+void AssemblerRISCVI::ld(Register rd, Register rs1, int16_t imm12) {
+  GenInstrLoad_ri(0b011, rd, rs1, imm12);
+}
+
+void AssemblerRISCVI::sd(Register source, Register base, int16_t imm12) {
+  GenInstrStore_rri(0b011, base, source, imm12);
+}
+
+void AssemblerRISCVI::addiw(Register rd, Register rs1, int16_t imm12) {
+  GenInstrI(0b000, OP_IMM_32, rd, rs1, imm12);
+}
+
+void AssemblerRISCVI::slliw(Register rd, Register rs1, uint8_t shamt) {
+  GenInstrShiftW_ri(0, 0b001, rd, rs1, shamt & 0x1f);
+}
+
+void AssemblerRISCVI::srliw(Register rd, Register rs1, uint8_t shamt) {
+  GenInstrShiftW_ri(0, 0b101, rd, rs1, shamt & 0x1f);
+}
+
+void AssemblerRISCVI::sraiw(Register rd, Register rs1, uint8_t shamt) {
+  GenInstrShiftW_ri(1, 0b101, rd, rs1, shamt & 0x1f);
+}
+
+void AssemblerRISCVI::addw(Register rd, Register rs1, Register rs2) {
+  GenInstrALUW_rr(0b0000000, 0b000, rd, rs1, rs2);
+}
+
+void AssemblerRISCVI::subw(Register rd, Register rs1, Register rs2) {
+  GenInstrALUW_rr(0b0100000, 0b000, rd, rs1, rs2);
+}
+
+void AssemblerRISCVI::sllw(Register rd, Register rs1, Register rs2) {
+  GenInstrALUW_rr(0b0000000, 0b001, rd, rs1, rs2);
+}
+
+void AssemblerRISCVI::srlw(Register rd, Register rs1, Register rs2) {
+  GenInstrALUW_rr(0b0000000, 0b101, rd, rs1, rs2);
+}
+
+void AssemblerRISCVI::sraw(Register rd, Register rs1, Register rs2) {
+  GenInstrALUW_rr(0b0100000, 0b101, rd, rs1, rs2);
+}
+
+#endif
+
+}  // namespace internal
+}  // namespace v8

src/codegen/riscv/base-riscv-i.h

+// Copyright 2022 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+#include "src/codegen/assembler.h"
+#include "src/codegen/riscv/base-assembler-riscv.h"
+#include "src/codegen/riscv/constant-riscv-i.h"
+#include "src/codegen/riscv/register-riscv.h"
+
+#ifndef V8_CODEGEN_RISCV_BASE_RISCV_I_H_
+#define V8_CODEGEN_RISCV_BASE_RISCV_I_H_
+
+namespace v8 {
+namespace internal {
+class AssemblerRISCVI : public AssemblerRiscvBase {
+ public:
+  void lui(Register rd, int32_t imm20);
+  void auipc(Register rd, int32_t imm20);
+
+  // Jumps
+  void jal(Register rd, int32_t imm20);
+  void jalr(Register rd, Register rs1, int16_t imm12);
+
+  // Branches
+  void beq(Register rs1, Register rs2, int16_t imm12);
+  void bne(Register rs1, Register rs2, int16_t imm12);
+  void blt(Register rs1, Register rs2, int16_t imm12);
+  void bge(Register rs1, Register rs2, int16_t imm12);
+  void bltu(Register rs1, Register rs2, int16_t imm12);
+  void bgeu(Register rs1, Register rs2, int16_t imm12);
+  // Loads
+  void lb(Register rd, Register rs1, int16_t imm12);
+  void lh(Register rd, Register rs1, int16_t imm12);
+  void lw(Register rd, Register rs1, int16_t imm12);
+  void lbu(Register rd, Register rs1, int16_t imm12);
+  void lhu(Register rd, Register rs1, int16_t imm12);
+
+  // Stores
+  void sb(Register source, Register base, int16_t imm12);
+  void sh(Register source, Register base, int16_t imm12);
+  void sw(Register source, Register base, int16_t imm12);
+
+  // Arithmetic with immediate
+  void addi(Register rd, Register rs1, int16_t imm12);
+  void slti(Register rd, Register rs1, int16_t imm12);
+  void sltiu(Register rd, Register rs1, int16_t imm12);
+  void xori(Register rd, Register rs1, int16_t imm12);
+  void ori(Register rd, Register rs1, int16_t imm12);
+  void andi(Register rd, Register rs1, int16_t imm12);
+  void slli(Register rd, Register rs1, uint8_t shamt);
+  void srli(Register rd, Register rs1, uint8_t shamt);
+  void srai(Register rd, Register rs1, uint8_t shamt);
+
+  // Arithmetic
+  void add(Register rd, Register rs1, Register rs2);
+  void sub(Register rd, Register rs1, Register rs2);
+  void sll(Register rd, Register rs1, Register rs2);
+  void slt(Register rd, Register rs1, Register rs2);
+  void sltu(Register rd, Register rs1, Register rs2);
+  void xor_(Register rd, Register rs1, Register rs2);
+  void srl(Register rd, Register rs1, Register rs2);
+  void sra(Register rd, Register rs1, Register rs2);
+  void or_(Register rd, Register rs1, Register rs2);
+  void and_(Register rd, Register rs1, Register rs2);
+
+  // Other pseudo instructions that are not part of RISCV pseudo assemly
+  void nor(Register rd, Register rs, Register rt) {
+    or_(rd, rs, rt);
+    not_(rd, rd);
+  }
+
+  // Memory fences
+  void fence(uint8_t pred, uint8_t succ);
+  void fence_tso();
+
+  // Environment call / break
+  void ecall();
+  void ebreak();
+
+  void sync() { fence(0b1111, 0b1111); }
+
+  // This is a de facto standard (as set by GNU binutils) 32-bit unimplemented
+  // instruction (i.e., it should always trap, if your implementation has
+  // invalid instruction traps).
+  void unimp();
+
+  static int JumpOffset(Instr instr);
+  static int AuipcOffset(Instr instr);
+  static int JalrOffset(Instr instr);
+  static int LoadOffset(Instr instr);
+
+  // Check if an instruction is a branch of some kind.
+  static bool IsBranch(Instr instr);
+  static bool IsNop(Instr instr);
+  static bool IsJump(Instr instr);
+  static bool IsJal(Instr instr);
+  static bool IsJalr(Instr instr);
+  static bool IsLui(Instr instr);
+  static bool IsAuipc(Instr instr);
+  static bool IsAddi(Instr instr);
+  static bool IsOri(Instr instr);
+  static bool IsSlli(Instr instr);
+  static bool IsLw(Instr instr);
+
+  inline int32_t branch_offset(Label* L) {
+    return branch_offset_helper(L, OffsetSize::kOffset13);
+  }
+  inline int32_t jump_offset(Label* L) {
+    return branch_offset_helper(L, OffsetSize::kOffset21);
+  }
+
+  // Branches
+  void beq(Register rs1, Register rs2, Label* L) {
+    beq(rs1, rs2, branch_offset(L));
+  }
+  void bne(Register rs1, Register rs2, Label* L) {
+    bne(rs1, rs2, branch_offset(L));
+  }
+  void blt(Register rs1, Register rs2, Label* L) {
+    blt(rs1, rs2, branch_offset(L));
+  }
+  void bge(Register rs1, Register rs2, Label* L) {
+    bge(rs1, rs2, branch_offset(L));
+  }
+  void bltu(Register rs1, Register rs2, Label* L) {
+    bltu(rs1, rs2, branch_offset(L));
+  }
+  void bgeu(Register rs1, Register rs2, Label* L) {
+    bgeu(rs1, rs2, branch_offset(L));
+  }
+
+  void beqz(Register rs, int16_t imm13) { beq(rs, zero_reg, imm13); }
+  void beqz(Register rs1, Label* L) { beqz(rs1, branch_offset(L)); }
+  void bnez(Register rs, int16_t imm13) { bne(rs, zero_reg, imm13); }
+  void bnez(Register rs1, Label* L) { bnez(rs1, branch_offset(L)); }
+  void blez(Register rs, int16_t imm13) { bge(zero_reg, rs, imm13); }
+  void blez(Register rs1, Label* L) { blez(rs1, branch_offset(L)); }
+  void bgez(Register rs, int16_t imm13) { bge(rs, zero_reg, imm13); }
+  void bgez(Register rs1, Label* L) { bgez(rs1, branch_offset(L)); }
+  void bltz(Register rs, int16_t imm13) { blt(rs, zero_reg, imm13); }
+  void bltz(Register rs1, Label* L) { bltz(rs1, branch_offset(L)); }
+  void bgtz(Register rs, int16_t imm13) { blt(zero_reg, rs, imm13); }
+
+  void bgtz(Register rs1, Label* L) { bgtz(rs1, branch_offset(L)); }
+  void bgt(Register rs1, Register rs2, int16_t imm13) { blt(rs2, rs1, imm13); }
+  void bgt(Register rs1, Register rs2, Label* L) {
+    bgt(rs1, rs2, branch_offset(L));
+  }
+  void ble(Register rs1, Register rs2, int16_t imm13) { bge(rs2, rs1, imm13); }
+  void ble(Register rs1, Register rs2, Label* L) {
+    ble(rs1, rs2, branch_offset(L));
+  }
+  void bgtu(Register rs1, Register rs2, int16_t imm13) {
+    bltu(rs2, rs1, imm13);
+  }
+  void bgtu(Register rs1, Register rs2, Label* L) {
+    bgtu(rs1, rs2, branch_offset(L));
+  }
+  void bleu(Register rs1, Register rs2, int16_t imm13) {
+    bgeu(rs2, rs1, imm13);
+  }
+  void bleu(Register rs1, Register rs2, Label* L) {
+    bleu(rs1, rs2, branch_offset(L));
+  }
+
+  void j(int32_t imm21) { jal(zero_reg, imm21); }
+  void j(Label* L) { j(jump_offset(L)); }
+  void b(Label* L) { j(L); }
+  void jal(int32_t imm21) { jal(ra, imm21); }
+  void jal(Label* L) { jal(jump_offset(L)); }
+  void jr(Register rs) { jalr(zero_reg, rs, 0); }
+  void jr(Register rs, int32_t imm12) { jalr(zero_reg, rs, imm12); }
+  void jalr(Register rs, int32_t imm12) { jalr(ra, rs, imm12); }
+  void jalr(Register rs) { jalr(ra, rs, 0); }
+  void ret() { jalr(zero_reg, ra, 0); }
+  void call(int32_t offset) {
+    auipc(ra, (offset >> 12) + ((offset & 0x800) >> 11));
+    jalr(ra, ra, offset << 20 >> 20);
+  }
+
+  void mv(Register rd, Register rs) { addi(rd, rs, 0); }
+  void not_(Register rd, Register rs) { xori(rd, rs, -1); }
+  void neg(Register rd, Register rs) { sub(rd, zero_reg, rs); }
+  void seqz(Register rd, Register rs) { sltiu(rd, rs, 1); }
+  void snez(Register rd, Register rs) { sltu(rd, zero_reg, rs); }
+  void sltz(Register rd, Register rs) { slt(rd, rs, zero_reg); }
+  void sgtz(Register rd, Register rs) { slt(rd, zero_reg, rs); }
+
+#if V8_TARGET_ARCH_RISCV64
+  void lwu(Register rd, Register rs1, int16_t imm12);
+  void ld(Register rd, Register rs1, int16_t imm12);
+  void sd(Register source, Register base, int16_t imm12);
+  void addiw(Register rd, Register rs1, int16_t imm12);
+  void slliw(Register rd, Register rs1, uint8_t shamt);
+  void srliw(Register rd, Register rs1, uint8_t shamt);
+  void sraiw(Register rd, Register rs1, uint8_t shamt);
+  void addw(Register rd, Register rs1, Register rs2);
+  void subw(Register rd, Register rs1, Register rs2);
+  void sllw(Register rd, Register rs1, Register rs2);
+  void srlw(Register rd, Register rs1, Register rs2);
+  void sraw(Register rd, Register rs1, Register rs2);
+  void negw(Register rd, Register rs) { subw(rd, zero_reg, rs); }
+  void sext_w(Register rd, Register rs) { addiw(rd, rs, 0); }
+
+  static bool IsAddiw(Instr instr);
+  static bool IsLd(Instr instr);
+#endif
+};
+
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_CODEGEN_RISCV_BASE_RISCV_I_H_

src/codegen/riscv/constant-riscv-a.h

+// Copyright 2022 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+#ifndef V8_CODEGEN_RISCV_CONSTANT_RISCV_A_H_
+#define V8_CODEGEN_RISCV_CONSTANT_RISCV_A_H_
+
+#include "src/codegen/riscv/base-constants-riscv.h"
+namespace v8 {
+namespace internal {
+
+enum OpcodeRISCVA : uint32_t {
+  // RV32A Standard Extension
+  RO_LR_W = AMO | (0b010 << kFunct3Shift) | (0b00010 << kFunct5Shift),
+  RO_SC_W = AMO | (0b010 << kFunct3Shift) | (0b00011 << kFunct5Shift),
+  RO_AMOSWAP_W = AMO | (0b010 << kFunct3Shift) | (0b00001 << kFunct5Shift),
+  RO_AMOADD_W = AMO | (0b010 << kFunct3Shift) | (0b00000 << kFunct5Shift),
+  RO_AMOXOR_W = AMO | (0b010 << kFunct3Shift) | (0b00100 << kFunct5Shift),
+  RO_AMOAND_W = AMO | (0b010 << kFunct3Shift) | (0b01100 << kFunct5Shift),
+  RO_AMOOR_W = AMO | (0b010 << kFunct3Shift) | (0b01000 << kFunct5Shift),
+  RO_AMOMIN_W = AMO | (0b010 << kFunct3Shift) | (0b10000 << kFunct5Shift),
+  RO_AMOMAX_W = AMO | (0b010 << kFunct3Shift) | (0b10100 << kFunct5Shift),
+  RO_AMOMINU_W = AMO | (0b010 << kFunct3Shift) | (0b11000 << kFunct5Shift),
+  RO_AMOMAXU_W = AMO | (0b010 << kFunct3Shift) | (0b11100 << kFunct5Shift),
+
+#ifdef V8_TARGET_ARCH_RISCV64
+  // RV64A Standard Extension (in addition to RV32A)
+  RO_LR_D = AMO | (0b011 << kFunct3Shift) | (0b00010 << kFunct5Shift),
+  RO_SC_D = AMO | (0b011 << kFunct3Shift) | (0b00011 << kFunct5Shift),
+  RO_AMOSWAP_D = AMO | (0b011 << kFunct3Shift) | (0b00001 << kFunct5Shift),
+  RO_AMOADD_D = AMO | (0b011 << kFunct3Shift) | (0b00000 << kFunct5Shift),
+  RO_AMOXOR_D = AMO | (0b011 << kFunct3Shift) | (0b00100 << kFunct5Shift),
+  RO_AMOAND_D = AMO | (0b011 << kFunct3Shift) | (0b01100 << kFunct5Shift),
+  RO_AMOOR_D = AMO | (0b011 << kFunct3Shift) | (0b01000 << kFunct5Shift),
+  RO_AMOMIN_D = AMO | (0b011 << kFunct3Shift) | (0b10000 << kFunct5Shift),
+  RO_AMOMAX_D = AMO | (0b011 << kFunct3Shift) | (0b10100 << kFunct5Shift),
+  RO_AMOMINU_D = AMO | (0b011 << kFunct3Shift) | (0b11000 << kFunct5Shift),
+  RO_AMOMAXU_D = AMO | (0b011 << kFunct3Shift) | (0b11100 << kFunct5Shift),
+#endif  // V8_TARGET_ARCH_RISCV64
+};
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_CODEGEN_RISCV_CONSTANT_RISCV_A_H_

src/codegen/riscv/constant-riscv-zifencei.h

+// Copyright 2022 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+#ifndef V8_CODEGEN_RISCV_CONSTANT_RISCV_ZIFENCEI_H_
+#define V8_CODEGEN_RISCV_CONSTANT_RISCV_ZIFENCEI_H_
+
+#include "src/codegen/riscv/base-constants-riscv.h"
+namespace v8 {
+namespace internal {
+enum OpcodeRISCVIFENCEI : uint32_t {
+  RO_FENCE_I = MISC_MEM | (0b001 << kFunct3Shift),
+};
+}
+}  // namespace v8
+#endif  // V8_CODEGEN_RISCV_CONSTANT_RISCV_ZIFENCEI_H_