[llvm] 76ccd1d - [AArch64] Don't form paired loads from epilogue operations on Windows
Eli Friedman via llvm-commits
llvm-commits at lists.llvm.org
Tue Oct 4 11:42:14 PDT 2022
Author: Eli Friedman
Date: 2022-10-04T11:41:59-07:00
New Revision: 76ccd1db735616af337d07ccfd88592b4d87e458
URL: https://github.com/llvm/llvm-project/commit/76ccd1db735616af337d07ccfd88592b4d87e458
DIFF: https://github.com/llvm/llvm-project/commit/76ccd1db735616af337d07ccfd88592b4d87e458.diff
LOG: [AArch64] Don't form paired loads from epilogue operations on Windows
AArch64LoadStoreOptimizer has a bunch of different guards to avoid
corrupting Windows SEH prologues/epilogues, but apparently we missed the
case of merging two instructions where the first instruction isn't part
of the epilogue, but the second instruction is.
Fixes issue discovered at https://reviews.llvm.org/D130049#3704064
Differential Revision: https://reviews.llvm.org/D134992
Added:
llvm/test/CodeGen/AArch64/wineh9.mir
Modified:
llvm/lib/Target/AArch64/AArch64LoadStoreOptimizer.cpp
Removed:
################################################################################
diff --git a/llvm/lib/Target/AArch64/AArch64LoadStoreOptimizer.cpp b/llvm/lib/Target/AArch64/AArch64LoadStoreOptimizer.cpp
index 1b8cd870ebe01..3b990dcdbd243 100644
--- a/llvm/lib/Target/AArch64/AArch64LoadStoreOptimizer.cpp
+++ b/llvm/lib/Target/AArch64/AArch64LoadStoreOptimizer.cpp
@@ -1275,6 +1275,11 @@ bool AArch64LoadStoreOpt::findMatchingStore(
return false;
}
+static bool needsWinCFI(const MachineFunction *MF) {
+ return MF->getTarget().getMCAsmInfo()->usesWindowsCFI() &&
+ MF->getFunction().needsUnwindTableEntry();
+}
+
// Returns true if FirstMI and MI are candidates for merging or pairing.
// Otherwise, returns false.
static bool areCandidatesToMergeOrPair(MachineInstr &FirstMI, MachineInstr &MI,
@@ -1289,6 +1294,10 @@ static bool areCandidatesToMergeOrPair(MachineInstr &FirstMI, MachineInstr &MI,
!TII->isLdStPairSuppressed(FirstMI) &&
"FirstMI shouldn't get here if either of these checks are true.");
+ if (needsWinCFI(MI.getMF()) && (MI.getFlag(MachineInstr::FrameSetup) ||
+ MI.getFlag(MachineInstr::FrameDestroy)))
+ return false;
+
unsigned OpcA = FirstMI.getOpcode();
unsigned OpcB = MI.getOpcode();
@@ -1896,11 +1905,6 @@ bool AArch64LoadStoreOpt::isMatchingUpdateInsn(MachineInstr &MemMI,
return false;
}
-static bool needsWinCFI(const MachineFunction *MF) {
- return MF->getTarget().getMCAsmInfo()->usesWindowsCFI() &&
- MF->getFunction().needsUnwindTableEntry();
-}
-
MachineBasicBlock::iterator AArch64LoadStoreOpt::findMatchingUpdateInsnForward(
MachineBasicBlock::iterator I, int UnscaledOffset, unsigned Limit) {
MachineBasicBlock::iterator E = I->getParent()->end();
diff --git a/llvm/test/CodeGen/AArch64/wineh9.mir b/llvm/test/CodeGen/AArch64/wineh9.mir
new file mode 100644
index 0000000000000..3586ea5bc43b4
--- /dev/null
+++ b/llvm/test/CodeGen/AArch64/wineh9.mir
@@ -0,0 +1,106 @@
+# RUN: llc -o - %s -mtriple=aarch64-windows -run-pass=aarch64-ldst-opt \
+# RUN: | FileCheck %s
+
+# CHECK: $x0 = LDRXui $sp, 1
+# CHECK: $x19 = frame-destroy LDRXui $sp, 2
+
+--- |
+ target triple = "aarch64-pc-windows-gnu"
+
+ define dso_local noundef i64 @_Z1fPFvPxEx(ptr nocapture noundef readonly %g, i64 noundef %x) uwtable {
+ entry:
+ %x.addr = alloca i64, align 8
+ store i64 %x, ptr %x.addr, align 8
+ call void %g(ptr noundef nonnull %x.addr)
+ call void asm sideeffect "", "~{x19}"()
+ %0 = load i64, ptr %x.addr, align 8
+ ret i64 %0
+ }
+...
+---
+name: _Z1fPFvPxEx
+alignment: 4
+exposesReturnsTwice: false
+legalized: false
+regBankSelected: false
+selected: false
+failedISel: false
+tracksRegLiveness: true
+hasWinCFI: true
+callsEHReturn: false
+callsUnwindInit: false
+hasEHCatchret: false
+hasEHScopes: false
+hasEHFunclets: false
+failsVerification: false
+tracksDebugUserValues: true
+registers: []
+liveins:
+ - { reg: '$x0', virtual-reg: '' }
+ - { reg: '$x1', virtual-reg: '' }
+frameInfo:
+ isFrameAddressTaken: false
+ isReturnAddressTaken: false
+ hasStackMap: false
+ hasPatchPoint: false
+ stackSize: 32
+ offsetAdjustment: 0
+ maxAlignment: 8
+ adjustsStack: true
+ hasCalls: true
+ stackProtector: ''
+ functionContext: ''
+ maxCallFrameSize: 0
+ cvBytesOfCalleeSavedRegisters: 0
+ hasOpaqueSPAdjustment: false
+ hasVAStart: false
+ hasMustTailInVarArgFunc: false
+ hasTailCall: false
+ localFrameSize: 8
+ savePoint: ''
+ restorePoint: ''
+fixedStack: []
+stack:
+ - { id: 0, name: x.addr, type: default, offset: -24, size: 8, alignment: 8,
+ stack-id: default, callee-saved-register: '', callee-saved-restored: true,
+ local-offset: -8, debug-info-variable: '', debug-info-expression: '',
+ debug-info-location: '' }
+ - { id: 1, name: '', type: spill-slot, offset: -8, size: 8, alignment: 8,
+ stack-id: default, callee-saved-register: '$lr', callee-saved-restored: true,
+ debug-info-variable: '', debug-info-expression: '', debug-info-location: '' }
+ - { id: 2, name: '', type: spill-slot, offset: -16, size: 8, alignment: 8,
+ stack-id: default, callee-saved-register: '$x19', callee-saved-restored: true,
+ debug-info-variable: '', debug-info-expression: '', debug-info-location: '' }
+callSites: []
+debugValueSubstitutions: []
+constants: []
+machineFunctionInfo:
+ hasRedZone: false
+body: |
+ bb.0.entry:
+ liveins: $x0, $x1, $x19, $lr
+
+ $sp = frame-setup SUBXri $sp, 32, 0
+ frame-setup SEH_StackAlloc 32
+ frame-setup STRXui killed $x19, $sp, 2 :: (store (s64) into %stack.2)
+ frame-setup SEH_SaveReg 19, 16
+ frame-setup STRXui killed $lr, $sp, 3 :: (store (s64) into %stack.1)
+ frame-setup SEH_SaveReg 30, 24
+ frame-setup SEH_PrologEnd
+ renamable $x8 = COPY $x0
+ STRXui killed renamable $x1, $sp, 1 :: (store (s64) into %ir.x.addr)
+ $x0 = ADDXri $sp, 8, 0
+ BLR killed renamable $x8, csr_aarch64_aapcs, implicit-def dead $lr, implicit $sp, implicit $x0, implicit-def $sp
+ INLINEASM &"", 1 /* sideeffect attdialect */, 12 /* clobber */, implicit-def dead early-clobber $x19
+ renamable $x0 = LDRXui $sp, 1 :: (dereferenceable load (s64) from %ir.x.addr)
+ frame-destroy SEH_EpilogStart
+ $lr = frame-destroy LDRXui $sp, 3 :: (load (s64) from %stack.1)
+ frame-destroy SEH_SaveReg 30, 24
+ $x19 = frame-destroy LDRXui $sp, 2 :: (load (s64) from %stack.2)
+ frame-destroy SEH_SaveReg 19, 16
+ $sp = frame-destroy ADDXri $sp, 32, 0
+ frame-destroy SEH_StackAlloc 32
+ frame-destroy SEH_EpilogEnd
+ RET_ReallyLR implicit $x0
+
+...
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