[arm] Fix SplitAddImmediate test on Armv6.

The movw/movt instructions are only available since Armv7. One of the
disassembly tests was expecting these instructions when, on Armv6, we generate a
load literal.

Change-Id: I2b11894b5de748fc185f341b0cd49fa518d005e5
Reviewed-on: https://chromium-review.googlesource.com/978143
Commit-Queue: Pierre Langlois <pierre.langlois@arm.com>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#52738}

test/cctest/test-disasm-arm.cc

@@ -28,6 +28,10 @@
 
 #include <stdlib.h>
 
+// The C++ style guide recommends using <re2> instead of <regex>. However, the
+// former isn't available in V8.
+#include <regex>  // NOLINT(build/c++11)
+
 #include "src/assembler-inl.h"
 #include "src/boxed-float.h"
 #include "src/debug/debug.h"
@@ -43,8 +47,11 @@
 namespace v8 {
 namespace internal {
 
+enum UseRegex { kRawString, kRegexString };
+
 template <typename... S>
-bool DisassembleAndCompare(byte* begin, S... expected_strings) {
+bool DisassembleAndCompare(byte* begin, UseRegex use_regex,
+                           S... expected_strings) {
   disasm::NameConverter converter;
   disasm::Disassembler disasm(converter);
   EmbeddedVector<char, 128> buffer;
@@ -62,6 +69,7 @@ bool DisassembleAndCompare(byte* begin, S... expected_strings) {
   bool test_passed = true;
 
   for (size_t i = 0; i < disassembly.size(); i++) {
+    if (use_regex == kRawString) {
       if (expected_disassembly[i] != disassembly[i]) {
         fprintf(stderr,
                 "expected: \n"
@@ -71,6 +79,19 @@ bool DisassembleAndCompare(byte* begin, S... expected_strings) {
                 expected_disassembly[i].c_str(), disassembly[i].c_str());
         test_passed = false;
       }
+    } else {
+      DCHECK_EQ(use_regex, kRegexString);
+      if (!std::regex_match(disassembly[i],
+                            std::regex(expected_disassembly[i]))) {
+        fprintf(stderr,
+                "expected (regex): \n"
+                "%s\n"
+                "disassembled: \n"
+                "%s\n\n",
+                expected_disassembly[i].c_str(), disassembly[i].c_str());
+        test_passed = false;
+      }
+    }
   }
 
   // Fail after printing expected disassembly if we expected a different number
@@ -98,14 +119,20 @@ bool DisassembleAndCompare(byte* begin, S... expected_strings) {
 // disassembles the generated instruction, comparing the output to the expected
 // value. If the comparison fails an error message is printed, but the test
 // continues to run until the end.
-#define COMPARE(asm_, ...)                                                \
+#define BASE_COMPARE(asm_, use_regex, ...)                             \
   {                                                                    \
     int pc_offset = assm.pc_offset();                                  \
     byte* progcounter = &buffer[pc_offset];                            \
     assm.asm_;                                                         \
-    if (!DisassembleAndCompare(progcounter, __VA_ARGS__)) failure = true; \
+    if (!DisassembleAndCompare(progcounter, use_regex, __VA_ARGS__)) { \
+      failure = true;                                                  \
+    }                                                                  \
   }
 
+#define COMPARE(asm_, ...) BASE_COMPARE(asm_, kRawString, __VA_ARGS__)
+
+#define COMPARE_REGEX(asm_, ...) BASE_COMPARE(asm_, kRegexString, __VA_ARGS__)
+
 // Force emission of any pending literals into a pool.
 #define EMIT_PENDING_LITERALS() \
   assm.CheckConstPool(true, false)
@@ -1488,7 +1515,9 @@ static void TestLoadLiteral(byte* buffer, Assembler* assm, bool* failure,
   snprintf(expected_string, sizeof(expected_string), expected_string_template,
            abs(offset), offset,
            progcounter + Instruction::kPCReadOffset + offset);
-  if (!DisassembleAndCompare(progcounter, expected_string)) *failure = true;
+  if (!DisassembleAndCompare(progcounter, kRawString, expected_string)) {
+    *failure = true;
+  }
 }
 
 
@@ -1591,6 +1620,7 @@ TEST(LoadStoreExclusive) {
 TEST(SplitAddImmediate) {
   SET_UP();
 
+  if (CpuFeatures::IsSupported(ARMv7)) {
     // Re-use the destination as a scratch.
     COMPARE(add(r0, r1, Operand(0x12345678)),
             "e3050678       movw r0, #22136",
@@ -1602,6 +1632,19 @@ TEST(SplitAddImmediate) {
             "e305c678       movw ip, #22136",
             "e341c234       movt ip, #4660",
             "e080000c       add r0, r0, ip");
+  } else {
+    // Re-use the destination as a scratch.
+    COMPARE_REGEX(add(r0, r1, Operand(0x12345678)),
+                  "e59f0[0-9a-f]{3}       "
+                      "ldr r0, \\[pc, #\\+[0-9]+\\] \\(addr 0x[0-9a-f]{8}\\)",
+                  "e0810000       add r0, r1, r0");
+
+    // Use ip as a scratch.
+    COMPARE_REGEX(add(r0, r0, Operand(0x12345678)),
+                  "e59fc[0-9a-f]{3}       "
+                      "ldr ip, \\[pc, #\\+[0-9]+\\] \\(addr 0x[0-9a-f]{8}\\)",
+                  "e080000c       add r0, r0, ip");
+  }
 
   // If ip is not available, split the operation into multiple additions.
   {