Shrinkify libcalls: use float versions of double libm functions with fast-math (bug 17850)
When a call to a double-precision libm function has fast-math semantics
(via function attribute for now because there is no IR-level FMF on calls),
we can avoid fpext/fptrunc operations and use the float version of the call
if the input and output are both float.
We already do this optimization using a command-line option; this patch just
adds the ability for fast-math to use the existing functionality.
I moved the cl::opt from InstructionCombining into SimplifyLibCalls because
it's only ever used internally to that class.
Modified the existing test cases to use the unsafe-fp-math attribute rather
than repeating all tests.
This patch should solve: http://llvm.org/bugs/show_bug.cgi?id=17850
Differential Revision: http://reviews.llvm.org/D5893
llvm-svn: 220390
diff --git a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
index 8d74976..c32294f 100644
--- a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
@@ -70,12 +70,6 @@
STATISTIC(NumFactor , "Number of factorizations");
STATISTIC(NumReassoc , "Number of reassociations");
-static cl::opt<bool>
- EnableUnsafeFPShrink("enable-double-float-shrink", cl::Hidden,
- cl::init(false),
- cl::desc("Enable unsafe double to float "
- "shrinking for math lib calls"));
-
// Initialization Routines
void llvm::initializeInstCombine(PassRegistry &Registry) {
initializeInstCombinerPass(Registry);
@@ -2945,7 +2939,7 @@
InstCombinerLibCallSimplifier(const DataLayout *DL,
const TargetLibraryInfo *TLI,
InstCombiner *IC)
- : LibCallSimplifier(DL, TLI, EnableUnsafeFPShrink) {
+ : LibCallSimplifier(DL, TLI) {
this->IC = IC;
}