[llvm] ecbf32d - [AArch64] Async unwind - Adjust unwind info in AArch64LoadStoreOptimizer
Momchil Velikov via llvm-commits
llvm-commits at lists.llvm.org
Wed Apr 13 09:25:37 PDT 2022
Author: Momchil Velikov
Date: 2022-04-13T17:04:53+01:00
New Revision: ecbf32dd88fc91b4fe709dc14bb3493dda6e8854
URL: https://github.com/llvm/llvm-project/commit/ecbf32dd88fc91b4fe709dc14bb3493dda6e8854
DIFF: https://github.com/llvm/llvm-project/commit/ecbf32dd88fc91b4fe709dc14bb3493dda6e8854.diff
LOG: [AArch64] Async unwind - Adjust unwind info in AArch64LoadStoreOptimizer
The AArch64LoadStoreOptimnizer pass may merge a register
increment/decrement with a following memory operation. In doing so, it
may break CFI by moving a stack pointer adjustment past the CFI
instruction that described *that* adjustment.
This patch fixes this issue by moving said CFI instruction after the
merged instruction, where the SP increment/decrement actually takes
place.
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D114547
Added:
Modified:
llvm/lib/Target/AArch64/AArch64LoadStoreOptimizer.cpp
llvm/test/CodeGen/AArch64/arm64-fp128.ll
llvm/test/CodeGen/AArch64/fcopysign.ll
llvm/test/CodeGen/AArch64/swifttail-call.ll
llvm/test/CodeGen/AArch64/tail-call.ll
Removed:
################################################################################
diff --git a/llvm/lib/Target/AArch64/AArch64LoadStoreOptimizer.cpp b/llvm/lib/Target/AArch64/AArch64LoadStoreOptimizer.cpp
index ccc6eff319e08..a7a1171026025 100644
--- a/llvm/lib/Target/AArch64/AArch64LoadStoreOptimizer.cpp
+++ b/llvm/lib/Target/AArch64/AArch64LoadStoreOptimizer.cpp
@@ -9,6 +9,12 @@
// This file contains a pass that performs load / store related peephole
// optimizations. This pass should be run after register allocation.
//
+// The pass runs after the PrologEpilogInserter where we emit the CFI
+// instructions. In order to preserve the correctness of the unwind informaiton,
+// the pass should not change the order of any two instructions, one of which
+// has the FrameSetup/FrameDestroy flag or, alternatively, apply an add-hoc fix
+// to unwind information.
+//
//===----------------------------------------------------------------------===//
#include "AArch64InstrInfo.h"
@@ -31,6 +37,7 @@
#include "llvm/CodeGen/TargetRegisterInfo.h"
#include "llvm/IR/DebugLoc.h"
#include "llvm/MC/MCAsmInfo.h"
+#include "llvm/MC/MCDwarf.h"
#include "llvm/MC/MCRegisterInfo.h"
#include "llvm/Pass.h"
#include "llvm/Support/CommandLine.h"
@@ -1762,6 +1769,26 @@ AArch64LoadStoreOpt::findMatchingInsn(MachineBasicBlock::iterator I,
return E;
}
+static MachineBasicBlock::iterator
+maybeMoveCFI(MachineInstr &MI, MachineBasicBlock::iterator MaybeCFI) {
+ if (MaybeCFI->getOpcode() != TargetOpcode::CFI_INSTRUCTION ||
+ !(MI.getFlag(MachineInstr::FrameSetup) ||
+ MI.getFlag(MachineInstr::FrameDestroy)) ||
+ getLdStBaseOp(MI).getReg() != AArch64::SP)
+ return MI.getParent()->end();
+
+ const MachineFunction &MF = *MI.getParent()->getParent();
+ unsigned CFIIndex = MaybeCFI->getOperand(0).getCFIIndex();
+ const MCCFIInstruction &CFI = MF.getFrameInstructions()[CFIIndex];
+ switch (CFI.getOperation()) {
+ case MCCFIInstruction::OpDefCfa:
+ case MCCFIInstruction::OpDefCfaOffset:
+ return MaybeCFI;
+ default:
+ return MI.getParent()->end();
+ }
+}
+
MachineBasicBlock::iterator
AArch64LoadStoreOpt::mergeUpdateInsn(MachineBasicBlock::iterator I,
MachineBasicBlock::iterator Update,
@@ -1771,6 +1798,12 @@ AArch64LoadStoreOpt::mergeUpdateInsn(MachineBasicBlock::iterator I,
"Unexpected base register update instruction to merge!");
MachineBasicBlock::iterator E = I->getParent()->end();
MachineBasicBlock::iterator NextI = next_nodbg(I, E);
+
+ // If updating the SP and the following instruction is CFA offset related CFI
+ // instruction move it after the merged instruction.
+ MachineBasicBlock::iterator CFI =
+ IsPreIdx ? maybeMoveCFI(*Update, next_nodbg(Update, E)) : E;
+
// Return the instruction following the merged instruction, which is
// the instruction following our unmerged load. Unless that's the add/sub
// instruction we're merging, in which case it's the one after that.
@@ -1808,7 +1841,10 @@ AArch64LoadStoreOpt::mergeUpdateInsn(MachineBasicBlock::iterator I,
.setMemRefs(I->memoperands())
.setMIFlags(I->mergeFlagsWith(*Update));
}
- (void)MIB;
+ if (CFI != E) {
+ MachineBasicBlock *MBB = I->getParent();
+ MBB->splice(std::next(MIB.getInstr()->getIterator()), MBB, CFI);
+ }
if (IsPreIdx) {
++NumPreFolded;
diff --git a/llvm/test/CodeGen/AArch64/arm64-fp128.ll b/llvm/test/CodeGen/AArch64/arm64-fp128.ll
index 597bc58d4aab5..5a25f128889cf 100644
--- a/llvm/test/CodeGen/AArch64/arm64-fp128.ll
+++ b/llvm/test/CodeGen/AArch64/arm64-fp128.ll
@@ -420,8 +420,8 @@ define dso_local void @test_extend() {
define fp128 @test_neg(fp128 %in) {
; CHECK-LABEL: test_neg:
; CHECK: // %bb.0:
-; CHECK-NEXT: .cfi_def_cfa_offset 16
; CHECK-NEXT: str q0, [sp, #-16]!
+; CHECK-NEXT: .cfi_def_cfa_offset 16
; CHECK-NEXT: ldrb w8, [sp, #15]
; CHECK-NEXT: eor w8, w8, #0x80
; CHECK-NEXT: strb w8, [sp, #15]
diff --git a/llvm/test/CodeGen/AArch64/fcopysign.ll b/llvm/test/CodeGen/AArch64/fcopysign.ll
index ff93ff77a1a0a..d633b641e0fe8 100644
--- a/llvm/test/CodeGen/AArch64/fcopysign.ll
+++ b/llvm/test/CodeGen/AArch64/fcopysign.ll
@@ -16,11 +16,11 @@ declare half @llvm.copysign.f16(half %a, half %b)
define fp128 @copysign0() {
; CHECK-LABEL: copysign0:
; CHECK: // %bb.0: // %entry
-; CHECK-NEXT: .cfi_def_cfa_offset 16
; CHECK-NEXT: adrp x8, .LCPI0_0
; CHECK-NEXT: ldr q0, [x8, :lo12:.LCPI0_0]
; CHECK-NEXT: adrp x8, val_double
; CHECK-NEXT: str q0, [sp, #-16]!
+; CHECK-NEXT: .cfi_def_cfa_offset 16
; CHECK-NEXT: ldr x8, [x8, :lo12:val_double]
; CHECK-NEXT: ldrb w9, [sp, #15]
; CHECK-NEXT: and x8, x8, #0x8000000000000000
@@ -32,11 +32,11 @@ define fp128 @copysign0() {
;
; CHECK-NONEON-LABEL: copysign0:
; CHECK-NONEON: // %bb.0: // %entry
-; CHECK-NONEON-NEXT: .cfi_def_cfa_offset 16
; CHECK-NONEON-NEXT: adrp x8, .LCPI0_0
; CHECK-NONEON-NEXT: ldr q0, [x8, :lo12:.LCPI0_0]
; CHECK-NONEON-NEXT: adrp x8, val_double
; CHECK-NONEON-NEXT: str q0, [sp, #-16]!
+; CHECK-NONEON-NEXT: .cfi_def_cfa_offset 16
; CHECK-NONEON-NEXT: ldr x8, [x8, :lo12:val_double]
; CHECK-NONEON-NEXT: ldrb w9, [sp, #15]
; CHECK-NONEON-NEXT: and x8, x8, #0x8000000000000000
@@ -55,11 +55,11 @@ entry:
define fp128 at copysign1() {
; CHECK-LABEL: copysign1:
; CHECK: // %bb.0: // %entry
-; CHECK-NEXT: .cfi_def_cfa_offset 16
; CHECK-NEXT: adrp x8, val_fp128
; CHECK-NEXT: ldr q0, [x8, :lo12:val_fp128]
; CHECK-NEXT: adrp x8, val_float
; CHECK-NEXT: str q0, [sp, #-16]!
+; CHECK-NEXT: .cfi_def_cfa_offset 16
; CHECK-NEXT: ldr w8, [x8, :lo12:val_float]
; CHECK-NEXT: ldrb w9, [sp, #15]
; CHECK-NEXT: and w8, w8, #0x80000000
@@ -71,11 +71,11 @@ define fp128 at copysign1() {
;
; CHECK-NONEON-LABEL: copysign1:
; CHECK-NONEON: // %bb.0: // %entry
-; CHECK-NONEON-NEXT: .cfi_def_cfa_offset 16
; CHECK-NONEON-NEXT: adrp x8, val_fp128
; CHECK-NONEON-NEXT: ldr q0, [x8, :lo12:val_fp128]
; CHECK-NONEON-NEXT: adrp x8, val_float
; CHECK-NONEON-NEXT: str q0, [sp, #-16]!
+; CHECK-NONEON-NEXT: .cfi_def_cfa_offset 16
; CHECK-NONEON-NEXT: ldr w8, [x8, :lo12:val_float]
; CHECK-NONEON-NEXT: ldrb w9, [sp, #15]
; CHECK-NONEON-NEXT: and w8, w8, #0x80000000
diff --git a/llvm/test/CodeGen/AArch64/swifttail-call.ll b/llvm/test/CodeGen/AArch64/swifttail-call.ll
index 5b612ab40008a..3efd9f98f40dc 100644
--- a/llvm/test/CodeGen/AArch64/swifttail-call.ll
+++ b/llvm/test/CodeGen/AArch64/swifttail-call.ll
@@ -36,6 +36,7 @@ define swifttailcc void @caller_to8_from0() #0 {
ret void
; COMMON: str {{x[0-9]+}}, [sp, #-16]!
+; COMMON-NEXT: .cfi_def_cfa_offset 16
; COMMON-NEXT: b callee_stack8
}
diff --git a/llvm/test/CodeGen/AArch64/tail-call.ll b/llvm/test/CodeGen/AArch64/tail-call.ll
index 83943801344b6..1a5599fcc508b 100644
--- a/llvm/test/CodeGen/AArch64/tail-call.ll
+++ b/llvm/test/CodeGen/AArch64/tail-call.ll
@@ -36,6 +36,7 @@ define fastcc void @caller_to8_from0() #0 {
ret void
; COMMON: str {{x[0-9]+}}, [sp, #-16]!
+; COMMON-NEXT: .cfi_def_cfa_offset 16
; COMMON-NEXT: b callee_stack8
}
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