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

src/ia32/lithium-codegen-ia32.cc

Index: src/ia32/lithium-codegen-ia32.cc
diff --git a/src/ia32/lithium-codegen-ia32.cc b/src/ia32/lithium-codegen-ia32.cc
index 898918f49e291174227a5aca7d20150e8c4be94d..82dc1f4e778c9aeccc844999be831691ff41ca9e 100644
--- a/src/ia32/lithium-codegen-ia32.cc
+++ b/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);