8255550: x86: Assembler::cmpq(Address dst, Register src) encoding is incorrect

shipilev · shipilev · commit 9e5bbff51d5f · 2020-10-29T14:19:56.000Z
Reviewed-by: kvn, eosterlund
diff --git a/src/hotspot/cpu/x86/assembler_x86.cpp b/src/hotspot/cpu/x86/assembler_x86.cpp
@@ -9803,7 +9803,7 @@ void Assembler::cmpq(Register dst, int32_t imm32) {
 
 void Assembler::cmpq(Address dst, Register src) {
   InstructionMark im(this);
-  emit_int16(get_prefixq(dst, src), 0x3B);
+  emit_int16(get_prefixq(dst, src), 0x39);
   emit_operand(src, dst);
 }
 

Original file line number	Diff line number	Diff line change
`@@ -9803,7 +9803,7 @@ void Assembler::cmpq(Register dst, int32_t imm32) {`
`9803`	`9803`
`9804`	`9804`	`void Assembler::cmpq(Address dst, Register src) {`
`9805`	`9805`	`InstructionMark im(this);`
`9806`		`- emit_int16(get_prefixq(dst, src), 0x3B);`
	`9806`	`+ emit_int16(get_prefixq(dst, src), 0x39);`
`9807`	`9807`	`emit_operand(src, dst);`
`9808`	`9808`	`}`
`9809`	`9809`