[mips] Fix atomic compare exchange.

We want to compare two inputs so need to perform the same
operation(ExtractBits) on them.

Change-Id: I6c81884fdd34dfa125b842f010cd40f8a6816a0f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1511132Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Yu Yin <xwafish@gmail.com>
Cr-Commit-Position: refs/heads/master@{#60136}

src/compiler/backend/mips/code-generator-mips.cc

@@ -482,6 +482,8 @@ void EmitWordLoadPoisoningIfNeeded(CodeGenerator* codegen,
     __ Ll(i.TempRegister(2), MemOperand(i.TempRegister(0), 0));                \
     __ ExtractBits(i.OutputRegister(0), i.TempRegister(2), i.TempRegister(1),  \
                    size, sign_extend);                                         \
+    __ ExtractBits(i.InputRegister(2), i.InputRegister(2), i.TempRegister(1),  \
+                   size, sign_extend);                                         \
     __ BranchShort(&exit, ne, i.InputRegister(2),                              \
                    Operand(i.OutputRegister(0)));                              \
     __ InsertBits(i.TempRegister(2), i.InputRegister(3), i.TempRegister(1),    \

src/compiler/backend/mips64/code-generator-mips64.cc

@@ -453,6 +453,8 @@ void EmitWordLoadPoisoningIfNeeded(CodeGenerator* codegen,
     __ load_linked(i.TempRegister(2), MemOperand(i.TempRegister(0), 0));       \
     __ ExtractBits(i.OutputRegister(0), i.TempRegister(2), i.TempRegister(1),  \
                    size, sign_extend);                                         \
+    __ ExtractBits(i.InputRegister(2), i.InputRegister(2), i.TempRegister(1),  \
+                   size, sign_extend);                                         \
     __ BranchShort(&exit, ne, i.InputRegister(2),                              \
                    Operand(i.OutputRegister(0)));                              \
     __ InsertBits(i.TempRegister(2), i.InputRegister(3), i.TempRegister(1),    \