[llvm] 0ab5b5b - Fix denormal-fp-math flag and attribute interaction
Matt Arsenault via llvm-commits
llvm-commits at lists.llvm.org
Fri Mar 27 12:49:12 PDT 2020
Author: Matt Arsenault
Date: 2020-03-27T12:48:58-07:00
New Revision: 0ab5b5b8581d9f2951575f7245824e6e4fc57dec
URL: https://github.com/llvm/llvm-project/commit/0ab5b5b8581d9f2951575f7245824e6e4fc57dec
DIFF: https://github.com/llvm/llvm-project/commit/0ab5b5b8581d9f2951575f7245824e6e4fc57dec.diff
LOG: Fix denormal-fp-math flag and attribute interaction
Make these behave the same way unsafe-fp-math and co. The command line
flag should add the attribute to functions that do not already have
it, and leave existing attributes. The attribute is the actual
implementation, but the flag is useful in some testing situations.
AMDGPU has a variety of tests with denormals enabled/disabled that
would require a painful level of test duplication without a flag. This
doesn't expose setting the separate input/output modes, or add a flag
for the f32 version yet.
Tests will be included in future patch.
Added:
Modified:
llvm/include/llvm/CodeGen/CommandFlags.h
llvm/include/llvm/Target/TargetOptions.h
llvm/lib/CodeGen/CommandFlags.cpp
llvm/lib/Target/ARM/ARMAsmPrinter.cpp
Removed:
################################################################################
diff --git a/llvm/include/llvm/CodeGen/CommandFlags.h b/llvm/include/llvm/CodeGen/CommandFlags.h
index cdec26879f73..f6d221689f6c 100644
--- a/llvm/include/llvm/CodeGen/CommandFlags.h
+++ b/llvm/include/llvm/CodeGen/CommandFlags.h
@@ -12,6 +12,7 @@
//
//===----------------------------------------------------------------------===//
+#include "llvm/ADT/FloatingPointMode.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/Intrinsics.h"
@@ -62,7 +63,7 @@ bool getEnableNoSignedZerosFPMath();
bool getEnableNoTrappingFPMath();
-llvm::FPDenormal::DenormalMode getDenormalFPMath();
+DenormalMode::DenormalModeKind getDenormalFPMath();
bool getEnableHonorSignDependentRoundingFPMath();
diff --git a/llvm/include/llvm/Target/TargetOptions.h b/llvm/include/llvm/Target/TargetOptions.h
index 7282040a352f..b7c5fb26583f 100644
--- a/llvm/include/llvm/Target/TargetOptions.h
+++ b/llvm/include/llvm/Target/TargetOptions.h
@@ -14,11 +14,13 @@
#ifndef LLVM_TARGET_TARGETOPTIONS_H
#define LLVM_TARGET_TARGETOPTIONS_H
+#include "llvm/ADT/FloatingPointMode.h"
#include "llvm/MC/MCTargetOptions.h"
#include <memory>
namespace llvm {
+ struct fltSemantics;
class MachineFunction;
class MemoryBuffer;
class Module;
@@ -57,15 +59,6 @@ namespace llvm {
};
}
- namespace FPDenormal {
- enum DenormalMode {
- IEEE, // IEEE 754 denormal numbers
- PreserveSign, // the sign of a flushed-to-zero number is preserved in
- // the sign of 0
- PositiveZero // denormals are flushed to positive zero
- };
- }
-
enum class BasicBlockSection {
All, // Use Basic Block Sections for all basic blocks. A section
// for every basic block can significantly bloat object file sizes.
@@ -134,8 +127,7 @@ namespace llvm {
EmulatedTLS(false), ExplicitEmulatedTLS(false), EnableIPRA(false),
EmitStackSizeSection(false), EnableMachineOutliner(false),
SupportsDefaultOutlining(false), EmitAddrsig(false),
- EmitCallSiteInfo(false), SupportsDebugEntryValues(false),
- EnableDebugEntryValues(false), ForceDwarfFrameSection(false) {}
+ FPDenormalMode(DenormalMode::IEEE, DenormalMode::IEEE) {}
/// PrintMachineCode - This flag is enabled when the -print-machineinstrs
/// option is specified on the command line, and should enable debugging
@@ -336,9 +328,32 @@ namespace llvm {
/// Which debugger to tune for.
DebuggerKind DebuggerTuning = DebuggerKind::Default;
- /// FPDenormalMode - This flags specificies which denormal numbers the code
- /// is permitted to require.
- FPDenormal::DenormalMode FPDenormalMode = FPDenormal::IEEE;
+ private:
+ /// Flushing mode to assume in default FP environment.
+ DenormalMode FPDenormalMode;
+
+ /// Flushing mode to assume in default FP environment, for float/vector of
+ /// float.
+ DenormalMode FP32DenormalMode;
+
+ public:
+ void setFPDenormalMode(DenormalMode Mode) {
+ FPDenormalMode = Mode;
+ }
+
+ void setFP32DenormalMode(DenormalMode Mode) {
+ FP32DenormalMode = Mode;
+ }
+
+ DenormalMode getRawFPDenormalMode() const {
+ return FPDenormalMode;
+ }
+
+ DenormalMode getRawFP32DenormalMode() const {
+ return FP32DenormalMode;
+ }
+
+ DenormalMode getDenormalMode(const fltSemantics &FPType) const;
/// What exception model to use
ExceptionHandling ExceptionModel = ExceptionHandling::None;
diff --git a/llvm/lib/CodeGen/CommandFlags.cpp b/llvm/lib/CodeGen/CommandFlags.cpp
index d5dc49a91177..d1540afc702a 100644
--- a/llvm/lib/CodeGen/CommandFlags.cpp
+++ b/llvm/lib/CodeGen/CommandFlags.cpp
@@ -54,7 +54,7 @@ CGOPT(bool, EnableNoInfsFPMath)
CGOPT(bool, EnableNoNaNsFPMath)
CGOPT(bool, EnableNoSignedZerosFPMath)
CGOPT(bool, EnableNoTrappingFPMath)
-CGOPT(FPDenormal::DenormalMode, DenormalFPMath)
+CGOPT(DenormalMode::DenormalModeKind, DenormalFPMath)
CGOPT(bool, EnableHonorSignDependentRoundingFPMath)
CGOPT(FloatABI::ABIType, FloatABIForCalls)
CGOPT(FPOpFusion::FPOpFusionMode, FuseFPOps)
@@ -212,17 +212,17 @@ codegen::RegisterCodeGenFlags::RegisterCodeGenFlags() {
cl::init(false));
CGBINDOPT(EnableNoTrappingFPMath);
- static cl::opt<FPDenormal::DenormalMode> DenormalFPMath(
+ static cl::opt<DenormalMode::DenormalModeKind> DenormalFPMath(
"denormal-fp-math",
cl::desc(
"Select which denormal numbers the code is permitted to require"),
- cl::init(FPDenormal::IEEE),
+ cl::init(DenormalMode::IEEE),
cl::values(
- clEnumValN(FPDenormal::IEEE, "ieee", "IEEE 754 denormal numbers"),
- clEnumValN(FPDenormal::PreserveSign, "preserve-sign",
+ clEnumValN(DenormalMode::IEEE, "ieee", "IEEE 754 denormal numbers"),
+ clEnumValN(DenormalMode::PreserveSign, "preserve-sign",
"the sign of a flushed-to-zero number is preserved "
"in the sign of 0"),
- clEnumValN(FPDenormal::PositiveZero, "positive-zero",
+ clEnumValN(DenormalMode::PositiveZero, "positive-zero",
"denormals are flushed to positive zero")));
CGBINDOPT(DenormalFPMath);
@@ -425,7 +425,12 @@ TargetOptions codegen::InitTargetOptionsFromCodeGenFlags() {
Options.NoNaNsFPMath = getEnableNoNaNsFPMath();
Options.NoSignedZerosFPMath = getEnableNoSignedZerosFPMath();
Options.NoTrappingFPMath = getEnableNoTrappingFPMath();
- Options.FPDenormalMode = getDenormalFPMath();
+
+ DenormalMode::DenormalModeKind DenormKind = getDenormalFPMath();
+
+ // FIXME: Should have separate input and output flags
+ Options.setFPDenormalMode(DenormalMode(DenormKind, DenormKind));
+
Options.HonorSignDependentRoundingFPMathOption =
getEnableHonorSignDependentRoundingFPMath();
if (getFloatABIForCalls() != FloatABI::Default)
@@ -563,6 +568,15 @@ void codegen::setFunctionAttributes(StringRef CPU, StringRef Features,
HANDLE_BOOL_ATTR(EnableNoNaNsFPMathView, "no-nans-fp-math");
HANDLE_BOOL_ATTR(EnableNoSignedZerosFPMathView, "no-signed-zeros-fp-math");
+ if (DenormalFPMathView->getNumOccurrences() > 0 &&
+ !F.hasFnAttribute("denormal-fp-math")) {
+ DenormalMode::DenormalModeKind DenormKind = getDenormalFPMath();
+
+ // FIXME: Command line flag should expose separate input/output modes.
+ NewAttrs.addAttribute("denormal-fp-math",
+ DenormalMode(DenormKind, DenormKind).str());
+ }
+
if (TrapFuncNameView->getNumOccurrences() > 0)
for (auto &B : F)
for (auto &I : B)
diff --git a/llvm/lib/Target/ARM/ARMAsmPrinter.cpp b/llvm/lib/Target/ARM/ARMAsmPrinter.cpp
index f6ccdf185695..1342f2bf5ad4 100644
--- a/llvm/lib/Target/ARM/ARMAsmPrinter.cpp
+++ b/llvm/lib/Target/ARM/ARMAsmPrinter.cpp
@@ -652,16 +652,13 @@ void ARMAsmPrinter::emitAttributes() {
}
// Set FP Denormals.
- if (checkDenormalAttributeConsistency(*MMI->getModule(),
- "denormal-fp-math",
- DenormalMode::getPreserveSign()) ||
- TM.Options.FPDenormalMode == FPDenormal::PreserveSign)
+ if (checkDenormalAttributeConsistency(*MMI->getModule(), "denormal-fp-math",
+ DenormalMode::getPreserveSign()))
ATS.emitAttribute(ARMBuildAttrs::ABI_FP_denormal,
ARMBuildAttrs::PreserveFPSign);
else if (checkDenormalAttributeConsistency(*MMI->getModule(),
"denormal-fp-math",
- DenormalMode::getPositiveZero()) ||
- TM.Options.FPDenormalMode == FPDenormal::PositiveZero)
+ DenormalMode::getPositiveZero()))
ATS.emitAttribute(ARMBuildAttrs::ABI_FP_denormal,
ARMBuildAttrs::PositiveZero);
else if (!TM.Options.UnsafeFPMath)
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