[AArch64][SVE] Avoid using the SVE stack size before it is determined (hopefully mostly a NFC) #147561
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This patch adds asserts to `getStackSizeSVE()` and
`getSVECalleeSavedStackSize()` to check they are only called after
the SVE stack size has been determined.
This patch then fixes issues in three places:
* AArch64FrameLowering::homogeneousPrologEpilog()
- This function is called before callee saves or SVE stack sizes
have been determined.
- This check has been updated to use isLikelyToHaveSVEStack().
This `isLikelyToHaveSVEStack()` conservatively returns if a function
is likely to have an SVE stack.
* produceCompactUnwindFrame()
- This function checked the SVE CS stack size before callee-saves
had been determined.
- This has been replaced with a more conservative isSVECC() check.
* AArch64FrameLowering::resolveFrameOffsetReference()
- This was hit by some MIR tests for post-PEI MIR.
- This case was fixed by adding "stackSizeSVE" to the YAML for
AArch64FunctionInfo.
MacDue
changed the title
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@llvm/pr-subscribers-backend-aarch64 @llvm/pr-subscribers-debuginfo Author: Benjamin Maxwell (MacDue) ChangesThis patch adds asserts to This patch then fixes issues in three places:
Full diff: https://github.com/llvm/llvm-project/pull/147561.diff 5 Files Affected:
diff --git a/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp b/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp
index 6f1ce5bdbe286..261261f476bcf 100644
--- a/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp
+++ b/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp
@@ -335,6 +335,26 @@ static Register findScratchNonCalleeSaveRegister(MachineBasicBlock *MBB,
bool HasCall = false);
static bool requiresSaveVG(const MachineFunction &MF);
+// Conservatively, returns true if the function is likely to have an SVE vectors
+// on the stack. This function is safe to be called before callee-saves or
+// object offsets have been determined.
+static bool isLikelyToHaveSVEStack(MachineFunction &MF) {
+ auto *AFI = MF.getInfo<AArch64FunctionInfo>();
+ if (AFI->isSVECC())
+ return true;
+
+ if (AFI->hasCalculatedStackSizeSVE())
+ return bool(getSVEStackSize(MF));
+
+ const MachineFrameInfo &MFI = MF.getFrameInfo();
+ for (int FI = MFI.getObjectIndexBegin(); FI < MFI.getObjectIndexEnd(); FI++) {
+ if (MFI.getStackID(FI) == TargetStackID::ScalableVector)
+ return true;
+ }
+
+ return false;
+}
+
/// Returns true if a homogeneous prolog or epilog code can be emitted
/// for the size optimization. If possible, a frame helper call is injected.
/// When Exit block is given, this check is for epilog.
@@ -350,8 +370,9 @@ bool AArch64FrameLowering::homogeneousPrologEpilog(
// TODO: Window is supported yet.
if (needsWinCFI(MF))
return false;
+
// TODO: SVE is not supported yet.
- if (getSVEStackSize(MF))
+ if (isLikelyToHaveSVEStack(MF))
return false;
// Bail on stack adjustment needed on return for simplicity.
@@ -2997,7 +3018,7 @@ static bool produceCompactUnwindFrame(MachineFunction &MF) {
!(Subtarget.getTargetLowering()->supportSwiftError() &&
Attrs.hasAttrSomewhere(Attribute::SwiftError)) &&
MF.getFunction().getCallingConv() != CallingConv::SwiftTail &&
- !requiresSaveVG(MF) && AFI->getSVECalleeSavedStackSize() == 0;
+ !requiresSaveVG(MF) && !AFI->isSVECC();
}
static bool invalidateWindowsRegisterPairing(unsigned Reg1, unsigned Reg2,
diff --git a/llvm/lib/Target/AArch64/AArch64MachineFunctionInfo.cpp b/llvm/lib/Target/AArch64/AArch64MachineFunctionInfo.cpp
index 4b04b80121ffa..b4197a04840b7 100644
--- a/llvm/lib/Target/AArch64/AArch64MachineFunctionInfo.cpp
+++ b/llvm/lib/Target/AArch64/AArch64MachineFunctionInfo.cpp
@@ -25,7 +25,10 @@ using namespace llvm;
yaml::AArch64FunctionInfo::AArch64FunctionInfo(
const llvm::AArch64FunctionInfo &MFI)
- : HasRedZone(MFI.hasRedZone()) {}
+ : HasRedZone(MFI.hasRedZone()),
+ StackSizeSVE(MFI.hasCalculatedStackSizeSVE()
+ ? std::optional<uint64_t>(MFI.getStackSizeSVE())
+ : std::nullopt) {}
void yaml::AArch64FunctionInfo::mappingImpl(yaml::IO &YamlIO) {
MappingTraits<AArch64FunctionInfo>::mapping(YamlIO, *this);
@@ -35,6 +38,8 @@ void AArch64FunctionInfo::initializeBaseYamlFields(
const yaml::AArch64FunctionInfo &YamlMFI) {
if (YamlMFI.HasRedZone)
HasRedZone = YamlMFI.HasRedZone;
+ if (YamlMFI.StackSizeSVE)
+ setStackSizeSVE(*YamlMFI.StackSizeSVE);
}
static std::pair<bool, bool> GetSignReturnAddress(const Function &F) {
diff --git a/llvm/lib/Target/AArch64/AArch64MachineFunctionInfo.h b/llvm/lib/Target/AArch64/AArch64MachineFunctionInfo.h
index e61f2280865b4..800787cc0b4f5 100644
--- a/llvm/lib/Target/AArch64/AArch64MachineFunctionInfo.h
+++ b/llvm/lib/Target/AArch64/AArch64MachineFunctionInfo.h
@@ -82,6 +82,7 @@ class AArch64FunctionInfo final : public MachineFunctionInfo {
unsigned CalleeSavedStackSize = 0;
unsigned SVECalleeSavedStackSize = 0;
bool HasCalleeSavedStackSize = false;
+ bool HasSVECalleeSavedStackSize = false;
/// Number of TLS accesses using the special (combinable)
/// _TLS_MODULE_BASE_ symbol.
@@ -306,7 +307,10 @@ class AArch64FunctionInfo final : public MachineFunctionInfo {
StackSizeSVE = S;
}
- uint64_t getStackSizeSVE() const { return StackSizeSVE; }
+ uint64_t getStackSizeSVE() const {
+ assert(hasCalculatedStackSizeSVE());
+ return StackSizeSVE;
+ }
bool hasStackFrame() const { return HasStackFrame; }
void setHasStackFrame(bool s) { HasStackFrame = s; }
@@ -400,8 +404,11 @@ class AArch64FunctionInfo final : public MachineFunctionInfo {
// Saves the CalleeSavedStackSize for SVE vectors in 'scalable bytes'
void setSVECalleeSavedStackSize(unsigned Size) {
SVECalleeSavedStackSize = Size;
+ HasSVECalleeSavedStackSize = true;
}
unsigned getSVECalleeSavedStackSize() const {
+ assert(HasSVECalleeSavedStackSize &&
+ "SVECalleeSavedStackSize has not been calculated");
return SVECalleeSavedStackSize;
}
@@ -592,6 +599,7 @@ class AArch64FunctionInfo final : public MachineFunctionInfo {
namespace yaml {
struct AArch64FunctionInfo final : public yaml::MachineFunctionInfo {
std::optional<bool> HasRedZone;
+ std::optional<uint64_t> StackSizeSVE;
AArch64FunctionInfo() = default;
AArch64FunctionInfo(const llvm::AArch64FunctionInfo &MFI);
@@ -603,6 +611,7 @@ struct AArch64FunctionInfo final : public yaml::MachineFunctionInfo {
template <> struct MappingTraits<AArch64FunctionInfo> {
static void mapping(IO &YamlIO, AArch64FunctionInfo &MFI) {
YamlIO.mapOptional("hasRedZone", MFI.HasRedZone);
+ YamlIO.mapOptional("stackSizeSVE", MFI.StackSizeSVE);
}
};
diff --git a/llvm/test/DebugInfo/AArch64/asan-stack-vars.mir b/llvm/test/DebugInfo/AArch64/asan-stack-vars.mir
index be3d1c0007998..5d644c3e5416c 100644
--- a/llvm/test/DebugInfo/AArch64/asan-stack-vars.mir
+++ b/llvm/test/DebugInfo/AArch64/asan-stack-vars.mir
@@ -365,6 +365,8 @@ frameInfo:
stackProtector: '%stack.0.StackGuardSlot'
maxCallFrameSize: 0
localFrameSize: 144
+machineFunctionInfo:
+ stackSizeSVE: 0
stack:
- { id: 0, name: StackGuardSlot, offset: -40, size: 8, alignment: 8,
stack-id: default, local-offset: -8 }
diff --git a/llvm/test/DebugInfo/AArch64/compiler-gen-bbs-livedebugvalues.mir b/llvm/test/DebugInfo/AArch64/compiler-gen-bbs-livedebugvalues.mir
index d97ef2214f054..013d93378a204 100644
--- a/llvm/test/DebugInfo/AArch64/compiler-gen-bbs-livedebugvalues.mir
+++ b/llvm/test/DebugInfo/AArch64/compiler-gen-bbs-livedebugvalues.mir
@@ -68,6 +68,8 @@ frameInfo:
adjustsStack: true
hasCalls: true
maxCallFrameSize: 0
+machineFunctionInfo:
+ stackSizeSVE: 0
stack:
- { id: 0, type: spill-slot, offset: -20, size: 4, alignment: 4, stack-id: default }
- { id: 1, type: spill-slot, offset: -8, size: 8, alignment: 8, stack-id: default,
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This patch adds asserts to
getStackSizeSVE()andgetSVECalleeSavedStackSize()to check they are only called after the SVE stack size has been determined.This patch then fixes issues in three places:
AArch64FrameLowering::homogeneousPrologEpilog()isLikelyToHaveSVEStack()isLikelyToHaveSVEStack()conservatively returns if a function is likely to have an SVE stackproduceCompactUnwindFrame()isSVECC()checkAArch64FrameLowering::resolveFrameOffsetReference()AArch64FunctionInfo