[llvm-commits] [llvm] r114148 - in /llvm/trunk: lib/Analysis/ConstantFolding.cpp test/Transforms/InstCombine/fold-calls.ll
Dan Gohman
gohman at apple.com
Thu Sep 16 18:38:06 PDT 2010
Author: djg
Date: Thu Sep 16 20:38:06 2010
New Revision: 114148
URL: http://llvm.org/viewvc/llvm-project?rev=114148&view=rev
Log:
Fix the folding of floating-point math library calls, like sin(infinity),
so that it detects errors on platforms where libm doesn't set errno.
It's still subject to host libm details though.
Added:
llvm/trunk/test/Transforms/InstCombine/fold-calls.ll
Modified:
llvm/trunk/lib/Analysis/ConstantFolding.cpp
Modified: llvm/trunk/lib/Analysis/ConstantFolding.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/ConstantFolding.cpp?rev=114148&r1=114147&r2=114148&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/ConstantFolding.cpp (original)
+++ llvm/trunk/lib/Analysis/ConstantFolding.cpp Thu Sep 16 20:38:06 2010
@@ -32,6 +32,7 @@
#include "llvm/Support/MathExtras.h"
#include <cerrno>
#include <cmath>
+#include <fenv.h>
using namespace llvm;
//===----------------------------------------------------------------------===//
@@ -1039,9 +1040,12 @@
static Constant *ConstantFoldFP(double (*NativeFP)(double), double V,
const Type *Ty) {
+ feclearexcept(FE_ALL_EXCEPT);
errno = 0;
V = NativeFP(V);
- if (errno != 0) {
+ if (errno != 0 ||
+ fetestexcept(FE_DIVBYZERO | FE_UNDERFLOW | FE_OVERFLOW | FE_INVALID)) {
+ feclearexcept(FE_ALL_EXCEPT);
errno = 0;
return 0;
}
@@ -1056,9 +1060,12 @@
static Constant *ConstantFoldBinaryFP(double (*NativeFP)(double, double),
double V, double W, const Type *Ty) {
+ feclearexcept(FE_ALL_EXCEPT);
errno = 0;
V = NativeFP(V, W);
- if (errno != 0) {
+ if (errno != 0 ||
+ fetestexcept(FE_DIVBYZERO | FE_UNDERFLOW | FE_OVERFLOW | FE_INVALID)) {
+ feclearexcept(FE_ALL_EXCEPT);
errno = 0;
return 0;
}
Added: llvm/trunk/test/Transforms/InstCombine/fold-calls.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/fold-calls.ll?rev=114148&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/fold-calls.ll (added)
+++ llvm/trunk/test/Transforms/InstCombine/fold-calls.ll Thu Sep 16 20:38:06 2010
@@ -0,0 +1,19 @@
+; RUN: opt -instcombine -S < %s | FileCheck %s
+
+; This shouldn't fold, because sin(inf) is invalid.
+; CHECK: @foo
+; CHECK: %t = call double @sin(double 0x7FF0000000000000)
+define double @foo() {
+ %t = call double @sin(double 0x7FF0000000000000)
+ ret double %t
+}
+
+; This should fold.
+; CHECK: @bar
+; CHECK: ret double 0x3FDA6026360C2F91
+define double @bar() {
+ %t = call double @sin(double 9.0)
+ ret double %t
+}
+
+declare double @sin(double)
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