[mips] Use t9 as the function call register.

xwafish · Commit Bot · commit 7889803e82d3 · 2019-09-26T13:44:23.000Z
on mips, we should use t9 when jump to a ExternalReference, because the callee function will consider t9 as the function start address. Change-Id: I56e2bf073fd24b2f3434dfd255d48264bfd0b2cd Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1826417 Auto-Submit: Yu Yin <xwafish@gmail.com> Commit-Queue: Jakob Kummerow <jkummerow@chromium.org> Reviewed-by: Jakob Kummerow <jkummerow@chromium.org> Cr-Commit-Position: refs/heads/master@{#63988}
diff --git a/src/codegen/mips/macro-assembler-mips.cc b/src/codegen/mips/macro-assembler-mips.cc
@@ -3853,10 +3853,8 @@ void TurboAssembler::Jump(Handle<Code> code, RelocInfo::Mode rmode,
 }
 
 void TurboAssembler::Jump(const ExternalReference& reference) {
-  UseScratchRegisterScope temps(this);
-  Register scratch = temps.Acquire();
-  li(scratch, reference);
-  Jump(scratch);
+  li(t9, reference);
+  Jump(t9);
 }
 
 void MacroAssembler::JumpIfIsInRange(Register value, unsigned lower_limit,
diff --git a/src/codegen/mips64/macro-assembler-mips64.cc b/src/codegen/mips64/macro-assembler-mips64.cc
@@ -4202,10 +4202,8 @@ void TurboAssembler::Jump(Handle<Code> code, RelocInfo::Mode rmode,
 }
 
 void TurboAssembler::Jump(const ExternalReference& reference) {
-  UseScratchRegisterScope temps(this);
-  Register scratch = temps.Acquire();
-  li(scratch, reference);
-  Jump(scratch);
+  li(t9, reference);
+  Jump(t9);
 }
 
 // Note: To call gcc-compiled C code on mips, you must call through t9.

Original file line number	Diff line number	Diff line change
`@@ -3853,10 +3853,8 @@ void TurboAssembler::Jump(Handle<Code> code, RelocInfo::Mode rmode,`
`3853`	`3853`	`}`
`3854`	`3854`
`3855`	`3855`	`void TurboAssembler::Jump(const ExternalReference& reference) {`
`3856`		`- UseScratchRegisterScope temps(this);`
`3857`		`- Register scratch = temps.Acquire();`
`3858`		`- li(scratch, reference);`
`3859`		`- Jump(scratch);`
	`3856`	`+ li(t9, reference);`
	`3857`	`+ Jump(t9);`
`3860`	`3858`	`}`
`3861`	`3859`
`3862`	`3860`	`void MacroAssembler::JumpIfIsInRange(Register value, unsigned lower_limit,`
Original file line number	Diff line number	Diff line change
`@@ -4202,10 +4202,8 @@ void TurboAssembler::Jump(Handle<Code> code, RelocInfo::Mode rmode,`
`4202`	`4202`	`}`
`4203`	`4203`
`4204`	`4204`	`void TurboAssembler::Jump(const ExternalReference& reference) {`
`4205`		`- UseScratchRegisterScope temps(this);`
`4206`		`- Register scratch = temps.Acquire();`
`4207`		`- li(scratch, reference);`
`4208`		`- Jump(scratch);`
	`4205`	`+ li(t9, reference);`
	`4206`	`+ Jump(t9);`
`4209`	`4207`	`}`
`4210`	`4208`
`4211`	`4209`	`// Note: To call gcc-compiled C code on mips, you must call through t9.`