PPC: clear upper bits of some inputs before emitting

Most register and immediate inputs are 5 bits long and 0x1f is used
as mask. Some immediates are byte sized in which case 0xff had to
be used.

Change-Id: Id7568732db9141743c839a2d1d21a27983547aba
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3009811Reviewed-by: Junliang Yan <junyan@redhat.com>
Commit-Queue: Milad Fa <mfarazma@redhat.com>
Cr-Commit-Position: refs/heads/master@{#75644}

src/codegen/ppc/assembler-ppc.cc

@@ -1912,7 +1912,8 @@ void Assembler::stxvx(const Simd128Register rt, const MemOperand& dst) {
 void Assembler::xxspltib(const Simd128Register rt, const Operand& imm) {
   int TX = 1;
   CHECK(is_uint8(imm.immediate()));
-  emit(XXSPLTIB | rt.code() * B21 | imm.immediate() * B11 | TX);
+  emit(XXSPLTIB | (rt.code() & 0x1F) * B21 | (imm.immediate() & 0xFF) * B11 |
+       TX);
 }
 
 // Pseudo instructions.

src/codegen/ppc/assembler-ppc.h

@@ -495,17 +495,19 @@ class Assembler : public AssemblerBase {
 
   inline void vx_form(Instr instr, Simd128Register rt, Simd128Register rb,
                       const Operand& imm) {
-    emit(instr | rt.code() * B21 | imm.immediate() * B16 | rb.code() * B11);
+    emit(instr | (rt.code() & 0x1F) * B21 | (imm.immediate() & 0x1F) * B16 |
+         (rb.code() & 0x1F) * B11);
   }
   inline void vx_form(Instr instr, Simd128Register rt, Simd128Register ra,
                       Simd128Register rb) {
-    emit(instr | rt.code() * B21 | ra.code() * B16 | rb.code() * B11);
+    emit(instr | (rt.code() & 0x1F) * B21 | ra.code() * B16 |
+         (rb.code() & 0x1F) * B11);
   }
   inline void vx_form(Instr instr, Simd128Register rt, Simd128Register rb) {
-    emit(instr | rt.code() * B21 | rb.code() * B11);
+    emit(instr | (rt.code() & 0x1F) * B21 | (rb.code() & 0x1F) * B11);
   }
   inline void vx_form(Instr instr, Simd128Register rt, const Operand& imm) {
-    emit(instr | rt.code() * B21 | (imm.immediate() & 0x1F) * B16);
+    emit(instr | (rt.code() & 0x1F) * B21 | (imm.immediate() & 0x1F) * B16);
   }
 
   PPC_VX_OPCODE_A_FORM_LIST(DECLARE_PPC_VX_INSTRUCTIONS_A_FORM)
@@ -528,8 +530,8 @@ class Assembler : public AssemblerBase {
 
   inline void va_form(Instr instr, Simd128Register rt, Simd128Register ra,
                       Simd128Register rb, Simd128Register rc) {
-    emit(instr | rt.code() * B21 | ra.code() * B16 | rb.code() * B11 |
-         rc.code() * B6);
+    emit(instr | (rt.code() & 0x1F) * B21 | (ra.code() & 0x1F) * B16 |
+         (rb.code() & 0x1F) * B11 | (rc.code() & 0x1F) * B6);
   }
 
   PPC_VA_OPCODE_A_FORM_LIST(DECLARE_PPC_VA_INSTRUCTIONS_A_FORM)
@@ -543,8 +545,8 @@ class Assembler : public AssemblerBase {
 
   inline void vc_form(Instr instr, Simd128Register rt, Simd128Register ra,
                       Simd128Register rb, int rc) {
-    emit(instr | rt.code() * B21 | ra.code() * B16 | rb.code() * B11 |
-         rc * B10);
+    emit(instr | (rt.code() & 0x1F) * B21 | (ra.code() & 0x1F) * B16 |
+         (rb.code() & 0x1F) * B11 | rc * B10);
   }
 
   PPC_VC_OPCODE_LIST(DECLARE_PPC_VC_INSTRUCTIONS)