Reapply af57dbf12e54 "Add support for options -frounding-math, ftrapping-math, -ffp-model=, and -ffp-exception-behavior="
Patch was reverted because https://bugs.llvm.org/show_bug.cgi?id=44048
The original patch is modified to set the strictfp IR attribute
explicitly in CodeGen instead of as a side effect of IRBuilder.
In the 2nd attempt to reapply there was a windows lit test fail, the
tests were fixed to use wildcard matching.
Differential Revision: https://reviews.llvm.org/D62731
diff --git a/clang/lib/CodeGen/CGCall.cpp b/clang/lib/CodeGen/CGCall.cpp
index ca6b1d4..657c926 100644
--- a/clang/lib/CodeGen/CGCall.cpp
+++ b/clang/lib/CodeGen/CGCall.cpp
@@ -4336,6 +4336,13 @@
Callee.getAbstractInfo(), Attrs, CallingConv,
/*AttrOnCallSite=*/true);
+ if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(CurFuncDecl))
+ if (FD->usesFPIntrin())
+ // All calls within a strictfp function are marked strictfp
+ Attrs =
+ Attrs.addAttribute(getLLVMContext(), llvm::AttributeList::FunctionIndex,
+ llvm::Attribute::StrictFP);
+
// Apply some call-site-specific attributes.
// TODO: work this into building the attribute set.
@@ -4385,6 +4392,13 @@
SmallVector<llvm::OperandBundleDef, 1> BundleList =
getBundlesForFunclet(CalleePtr);
+ if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(CurFuncDecl))
+ if (FD->usesFPIntrin())
+ // All calls within a strictfp function are marked strictfp
+ Attrs =
+ Attrs.addAttribute(getLLVMContext(), llvm::AttributeList::FunctionIndex,
+ llvm::Attribute::StrictFP);
+
// Emit the actual call/invoke instruction.
llvm::CallBase *CI;
if (!InvokeDest) {
diff --git a/clang/lib/CodeGen/CodeGenFunction.cpp b/clang/lib/CodeGen/CodeGenFunction.cpp
index 7f3be89..fd30208 100644
--- a/clang/lib/CodeGen/CodeGenFunction.cpp
+++ b/clang/lib/CodeGen/CodeGenFunction.cpp
@@ -33,6 +33,8 @@
#include "clang/Frontend/FrontendDiagnostic.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/Dominators.h"
+#include "llvm/IR/FPEnv.h"
+#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Intrinsics.h"
#include "llvm/IR/MDBuilder.h"
#include "llvm/IR/Operator.h"
@@ -87,6 +89,7 @@
FMF.setAllowReassoc();
}
Builder.setFastMathFlags(FMF);
+ SetFPModel();
}
CodeGenFunction::~CodeGenFunction() {
@@ -102,6 +105,51 @@
CGM.getOpenMPRuntime().functionFinished(*this);
}
+// Map the LangOption for rounding mode into
+// the corresponding enum in the IR.
+static llvm::fp::RoundingMode ToConstrainedRoundingMD(
+ LangOptions::FPRoundingModeKind Kind) {
+
+ switch (Kind) {
+ case LangOptions::FPR_ToNearest: return llvm::fp::rmToNearest;
+ case LangOptions::FPR_Downward: return llvm::fp::rmDownward;
+ case LangOptions::FPR_Upward: return llvm::fp::rmUpward;
+ case LangOptions::FPR_TowardZero: return llvm::fp::rmTowardZero;
+ case LangOptions::FPR_Dynamic: return llvm::fp::rmDynamic;
+ }
+ llvm_unreachable("Unsupported FP RoundingMode");
+}
+
+// Map the LangOption for exception behavior into
+// the corresponding enum in the IR.
+static llvm::fp::ExceptionBehavior ToConstrainedExceptMD(
+ LangOptions::FPExceptionModeKind Kind) {
+
+ switch (Kind) {
+ case LangOptions::FPE_Ignore: return llvm::fp::ebIgnore;
+ case LangOptions::FPE_MayTrap: return llvm::fp::ebMayTrap;
+ case LangOptions::FPE_Strict: return llvm::fp::ebStrict;
+ }
+ llvm_unreachable("Unsupported FP Exception Behavior");
+}
+
+void CodeGenFunction::SetFPModel() {
+ auto fpRoundingMode = ToConstrainedRoundingMD(
+ getLangOpts().getFPRoundingMode());
+ auto fpExceptionBehavior = ToConstrainedExceptMD(
+ getLangOpts().getFPExceptionMode());
+
+ if (fpExceptionBehavior == llvm::fp::ebIgnore &&
+ fpRoundingMode == llvm::fp::rmToNearest)
+ // Constrained intrinsics are not used.
+ ;
+ else {
+ Builder.setIsFPConstrained(true);
+ Builder.setDefaultConstrainedRounding(fpRoundingMode);
+ Builder.setDefaultConstrainedExcept(fpExceptionBehavior);
+ }
+}
+
CharUnits CodeGenFunction::getNaturalPointeeTypeAlignment(QualType T,
LValueBaseInfo *BaseInfo,
TBAAAccessInfo *TBAAInfo) {
@@ -823,6 +871,10 @@
if (FD->isMain())
Fn->addFnAttr(llvm::Attribute::NoRecurse);
+ if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(D))
+ if (FD->usesFPIntrin())
+ Fn->addFnAttr(llvm::Attribute::StrictFP);
+
// If a custom alignment is used, force realigning to this alignment on
// any main function which certainly will need it.
if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(D))
diff --git a/clang/lib/CodeGen/CodeGenFunction.h b/clang/lib/CodeGen/CodeGenFunction.h
index 7a2627c..8f99b09 100644
--- a/clang/lib/CodeGen/CodeGenFunction.h
+++ b/clang/lib/CodeGen/CodeGenFunction.h
@@ -4169,6 +4169,9 @@
/// point operation, expressed as the maximum relative error in ulp.
void SetFPAccuracy(llvm::Value *Val, float Accuracy);
+ /// SetFPModel - Control floating point behavior via fp-model settings.
+ void SetFPModel();
+
private:
llvm::MDNode *getRangeForLoadFromType(QualType Ty);
void EmitReturnOfRValue(RValue RV, QualType Ty);