[llvm] r261650 - [AArch64] Fix fastcc -tailcallopt epilog code generation.
Geoff Berry via llvm-commits
llvm-commits at lists.llvm.org
Tue Feb 23 08:54:38 PST 2016
Author: gberry
Date: Tue Feb 23 10:54:36 2016
New Revision: 261650
URL: http://llvm.org/viewvc/llvm-project?rev=261650&view=rev
Log:
[AArch64] Fix fastcc -tailcallopt epilog code generation.
Summary:
Fix a bug in epilog generation where the incoming stack arguments were
not being popped for fastcc functions when -tailcallopt was passed.
Reviewers: t.p.northover, mcrosier, jmolloy, rengolin
Subscribers: aemerson, rengolin, mcrosier, llvm-commits
Differential Revision: http://reviews.llvm.org/D16894
Modified:
llvm/trunk/lib/Target/AArch64/AArch64FrameLowering.cpp
llvm/trunk/test/CodeGen/AArch64/fastcc.ll
Modified: llvm/trunk/lib/Target/AArch64/AArch64FrameLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/AArch64/AArch64FrameLowering.cpp?rev=261650&r1=261649&r2=261650&view=diff
==============================================================================
--- llvm/trunk/lib/Target/AArch64/AArch64FrameLowering.cpp (original)
+++ llvm/trunk/lib/Target/AArch64/AArch64FrameLowering.cpp Tue Feb 23 10:54:36 2016
@@ -607,7 +607,6 @@ void AArch64FrameLowering::emitEpilogue(
//
// AArch64TargetLowering::LowerCall figures out ArgumentPopSize and keeps
// it as the 2nd argument of AArch64ISD::TC_RETURN.
- NumBytes += ArgumentPopSize;
// Move past the restores of the callee-saved registers.
MachineBasicBlock::iterator LastPopI = MBB.getFirstTerminator();
@@ -623,12 +622,23 @@ void AArch64FrameLowering::emitEpilogue(
assert(NumBytes >= 0 && "Negative stack allocation size!?");
if (!hasFP(MF)) {
+ bool RedZone = canUseRedZone(MF);
// If this was a redzone leaf function, we don't need to restore the
- // stack pointer.
- if (!canUseRedZone(MF))
- emitFrameOffset(MBB, LastPopI, DL, AArch64::SP, AArch64::SP, NumBytes,
- TII, MachineInstr::FrameDestroy);
- return;
+ // stack pointer (but we may need to pop stack args for fastcc).
+ if (RedZone && ArgumentPopSize == 0)
+ return;
+
+ bool NoCalleeSaveRestore = AFI->getCalleeSavedStackSize() == 0;
+ int StackRestoreBytes = RedZone ? 0 : NumBytes;
+ if (NoCalleeSaveRestore)
+ StackRestoreBytes += ArgumentPopSize;
+ emitFrameOffset(MBB, LastPopI, DL, AArch64::SP, AArch64::SP,
+ StackRestoreBytes, TII, MachineInstr::FrameDestroy);
+ // If we were able to combine the local stack pop with the argument pop,
+ // then we're done.
+ if (NoCalleeSaveRestore || ArgumentPopSize == 0)
+ return;
+ NumBytes = 0;
}
// Restore the original stack pointer.
@@ -639,6 +649,13 @@ void AArch64FrameLowering::emitEpilogue(
emitFrameOffset(MBB, LastPopI, DL, AArch64::SP, AArch64::FP,
-AFI->getCalleeSavedStackSize() + 16, TII,
MachineInstr::FrameDestroy);
+
+ // This must be placed after the callee-save restore code because that code
+ // assumes the SP is at the same location as it was after the callee-save save
+ // code in the prologue.
+ if (ArgumentPopSize)
+ emitFrameOffset(MBB, MBB.getFirstTerminator(), DL, AArch64::SP, AArch64::SP,
+ ArgumentPopSize, TII, MachineInstr::FrameDestroy);
}
/// getFrameIndexReference - Provide a base+offset reference to an FI slot for
Modified: llvm/trunk/test/CodeGen/AArch64/fastcc.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AArch64/fastcc.ll?rev=261650&r1=261649&r2=261650&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/AArch64/fastcc.ll (original)
+++ llvm/trunk/test/CodeGen/AArch64/fastcc.ll Tue Feb 23 10:54:36 2016
@@ -1,5 +1,6 @@
; RUN: llc -verify-machineinstrs < %s -mtriple=aarch64-none-linux-gnu -tailcallopt | FileCheck %s -check-prefix CHECK-TAIL
; RUN: llc -verify-machineinstrs < %s -mtriple=aarch64-none-linux-gnu | FileCheck %s
+; RUN: llc -verify-machineinstrs < %s -mtriple=aarch64-none-linux-gnu -tailcallopt -aarch64-redzone | FileCheck %s -check-prefix CHECK-TAIL-RZ
; Without tailcallopt fastcc still means the caller cleans up the
; stack, so try to make sure this is respected.
@@ -97,6 +98,7 @@ define fastcc void @func_stack8([8 x i32
; CHECK-TAIL: mov sp, x29
; CHECK-TAIL-NEXT: ldp x29, x30, [sp], #16
+; CHECK-TAIL-NEXT: add sp, sp, #16
; CHECK-TAIL-NEXT: ret
}
@@ -140,5 +142,95 @@ define fastcc void @func_stack32([8 x i3
; CHECK-TAIL: mov sp, x29
; CHECK-TAIL-NEXT: ldp x29, x30, [sp], #16
+; CHECK-TAIL-NEXT: add sp, sp, #32
; CHECK-TAIL-NEXT: ret
}
+
+; Check that arg stack pop is done after callee-save restore when no frame pointer is used.
+define fastcc void @func_stack32_leaf([8 x i32], i128 %stacked0, i128 %stacked1) {
+; CHECK-LABEL: func_stack32_leaf:
+; CHECK: str x20, [sp, #-16]!
+; CHECK: nop
+; CHECK-NEXT: //NO_APP
+; CHECK-NEXT: ldr x20, [sp], #16
+; CHECK-NEXT: ret
+
+; CHECK-TAIL-LABEL: func_stack32_leaf:
+; CHECK-TAIL: str x20, [sp, #-16]!
+; CHECK-TAIL: nop
+; CHECK-TAIL-NEXT: //NO_APP
+; CHECK-TAIL-NEXT: ldr x20, [sp], #16
+; CHECK-TAIL-NEXT: add sp, sp, #32
+; CHECK-TAIL-NEXT: ret
+
+; CHECK-TAIL-RZ-LABEL: func_stack32_leaf:
+; CHECK-TAIL-RZ: str x20, [sp, #-16]!
+; CHECK-TAIL-RZ-NOT: sub sp, sp
+; CHECK-TAIL-RZ: nop
+; CHECK-TAIL-RZ-NEXT: //NO_APP
+; CHECK-TAIL-RZ-NEXT: ldr x20, [sp], #16
+; CHECK-TAIL-RZ-NEXT: add sp, sp, #32
+; CHECK-TAIL-RZ-NEXT: ret
+
+ ; Make sure there is a callee-save register to save/restore.
+ call void asm sideeffect "nop", "~{x20}"() nounwind
+ ret void
+}
+
+; Check that arg stack pop is done after callee-save restore when no frame pointer is used.
+define fastcc void @func_stack32_leaf_local([8 x i32], i128 %stacked0, i128 %stacked1) {
+; CHECK-LABEL: func_stack32_leaf_local:
+; CHECK: str x20, [sp, #-16]!
+; CHECK-NEXT: sub sp, sp, #16
+; CHECK: nop
+; CHECK-NEXT: //NO_APP
+; CHECK-NEXT: add sp, sp, #16
+; CHECK-NEXT: ldr x20, [sp], #16
+; CHECK-NEXT: ret
+
+; CHECK-TAIL-LABEL: func_stack32_leaf_local:
+; CHECK-TAIL: str x20, [sp, #-16]!
+; CHECK-TAIL-NEXT: sub sp, sp, #16
+; CHECK-TAIL: nop
+; CHECK-TAIL-NEXT: //NO_APP
+; CHECK-TAIL-NEXT: add sp, sp, #16
+; CHECK-TAIL-NEXT: ldr x20, [sp], #16
+; CHECK-TAIL-NEXT: add sp, sp, #32
+; CHECK-TAIL-NEXT: ret
+
+; CHECK-TAIL-RZ-LABEL: func_stack32_leaf_local:
+; CHECK-TAIL-RZ: str x20, [sp, #-16]!
+; CHECK-TAIL-RZ-NOT: sub sp, sp
+; CHECK-TAIL-RZ: nop
+; CHECK-TAIL-RZ-NEXT: //NO_APP
+; CHECK-TAIL-RZ-NEXT: ldr x20, [sp], #16
+; CHECK-TAIL-RZ-NEXT: add sp, sp, #32
+; CHECK-TAIL-RZ-NEXT: ret
+
+ %val0 = alloca [2 x i64], align 8
+
+ ; Make sure there is a callee-save register to save/restore.
+ call void asm sideeffect "nop", "~{x20}"() nounwind
+ ret void
+}
+
+; Check that arg stack pop is done after callee-save restore when no frame pointer is used.
+define fastcc void @func_stack32_leaf_local_nocs([8 x i32], i128 %stacked0, i128 %stacked1) {
+; CHECK-LABEL: func_stack32_leaf_local_nocs:
+; CHECK: sub sp, sp, #16
+; CHECK: add sp, sp, #16
+; CHECK-NEXT: ret
+
+; CHECK-TAIL-LABEL: func_stack32_leaf_local_nocs:
+; CHECK-TAIL: sub sp, sp, #16
+; CHECK-TAIL: add sp, sp, #48
+; CHECK-TAIL-NEXT: ret
+
+; CHECK-TAIL-RZ-LABEL: func_stack32_leaf_local_nocs:
+; CHECK-TAIL-RZ: add sp, sp, #32
+; CHECK-TAIL-RZ-NEXT: ret
+
+ %val0 = alloca [2 x i64], align 8
+
+ ret void
+}
More information about the llvm-commits
mailing list