Remove the extra instruction that copy from sp

PanTao2 · PanTao2 · commit 6606db97307f · 2025-11-18T15:59:31.000+08:00
diff --git a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
@@ -29109,9 +29109,7 @@ SDValue AArch64TargetLowering::emitStackGuardMixCookie(SelectionDAG &DAG,
   if (FailureBB) {
     return DAG.getNode(
         ISD::ADD, DL, Val.getValueType(),
-        DAG.getCopyFromReg(DAG.getEntryNode(), DL,
-                           getStackPointerRegisterToSaveRestore(), MVT::i64),
-        Val);
+        DAG.getRegister(getStackPointerRegisterToSaveRestore(), MVT::i64), Val);
   }
   return Val;
 }
diff --git a/llvm/test/CodeGen/AArch64/stack-protector-target.ll b/llvm/test/CodeGen/AArch64/stack-protector-target.ll
@@ -35,8 +35,7 @@ declare void @_Z7CapturePi(ptr)
 ; WINDOWS-AARCH64: str x8, [sp, #8]
 ; WINDOWS-AARCH64: bl  _Z7CapturePi
 ; WINDOWS-AARCH64: ldr x8, [sp, #8]
-; WINDOWS-AARCH64: mov x9, sp
-; WINDOWS-AARCH64: add x0, x9, x8
+; WINDOWS-AARCH64: add x0, sp, x8
 ; WINDOWS-AARCH64: bl  __security_check_cookie
 
 ; WINDOWS-ARM64EC: adrp x8, __security_cookie
@@ -45,6 +44,5 @@ declare void @_Z7CapturePi(ptr)
 ; WINDOWS-ARM64EC: str x8, [sp, #8]
 ; WINDOWS-ARM64EC: bl "#_Z7CapturePi"
 ; WINDOWS-ARM64EC: ldr x8, [sp, #8]
-; WINDOWS-ARM64EC: mov x9, sp
-; WINDOWS-ARM64EC: add x0, x9, x8
+; WINDOWS-ARM64EC: add x0, sp, x8
 ; WINDOWS-ARM64EC: bl "#__security_check_cookie_arm64ec"

Original file line number	Diff line number	Diff line change
`@@ -29109,9 +29109,7 @@ SDValue AArch64TargetLowering::emitStackGuardMixCookie(SelectionDAG &DAG,`
`29109`	`29109`	`if (FailureBB) {`
`29110`	`29110`	`return DAG.getNode(`
`29111`	`29111`	`ISD::ADD, DL, Val.getValueType(),`
`29112`		`- DAG.getCopyFromReg(DAG.getEntryNode(), DL,`
`29113`		`- getStackPointerRegisterToSaveRestore(), MVT::i64),`
`29114`		`- Val);`
	`29112`	`+ DAG.getRegister(getStackPointerRegisterToSaveRestore(), MVT::i64), Val);`
`29115`	`29113`	`}`
`29116`	`29114`	`return Val;`
`29117`	`29115`	`}`