ia32: Calls to the TranscendentalCacheStub must ensure that esi is set to something safe.

BUG=v8:2827
R=verwaest@chromium.org

Review URL: https://codereview.chromium.org/22863002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@16154 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/ia32/lithium-codegen-ia32.cc

@@ -4092,6 +4092,9 @@ void LCodeGen::DoMathExp(LMathExp* instr) {
 
 void LCodeGen::DoMathTan(LMathTan* instr) {
   ASSERT(ToDoubleRegister(instr->result()).is(xmm1));
+  // Set the context register to a GC-safe fake value. Clobbering it is
+  // OK because this instruction is marked as a call.
+  __ Set(esi, Immediate(0));
   TranscendentalCacheStub stub(TranscendentalCache::TAN,
                                TranscendentalCacheStub::UNTAGGED);
   CallCode(stub.GetCode(isolate()), RelocInfo::CODE_TARGET, instr);
@@ -4100,6 +4103,9 @@ void LCodeGen::DoMathTan(LMathTan* instr) {
 
 void LCodeGen::DoMathCos(LMathCos* instr) {
   ASSERT(ToDoubleRegister(instr->result()).is(xmm1));
+  // Set the context register to a GC-safe fake value. Clobbering it is
+  // OK because this instruction is marked as a call.
+  __ Set(esi, Immediate(0));
   TranscendentalCacheStub stub(TranscendentalCache::COS,
                                TranscendentalCacheStub::UNTAGGED);
   CallCode(stub.GetCode(isolate()), RelocInfo::CODE_TARGET, instr);
@@ -4108,6 +4114,9 @@ void LCodeGen::DoMathCos(LMathCos* instr) {
 
 void LCodeGen::DoMathSin(LMathSin* instr) {
   ASSERT(ToDoubleRegister(instr->result()).is(xmm1));
+  // Set the context register to a GC-safe fake value. Clobbering it is
+  // OK because this instruction is marked as a call.
+  __ Set(esi, Immediate(0));
   TranscendentalCacheStub stub(TranscendentalCache::SIN,
                                TranscendentalCacheStub::UNTAGGED);
   CallCode(stub.GetCode(isolate()), RelocInfo::CODE_TARGET, instr);