Make loop-idiom use TargetLibraryInfo to determine whether it is allowed
to hack on memset, memcpy etc.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125974 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/LoopIdiomRecognize.cpp b/lib/Transforms/Scalar/LoopIdiomRecognize.cpp
index f6dcfb8..d15e58d 100644
--- a/lib/Transforms/Scalar/LoopIdiomRecognize.cpp
+++ b/lib/Transforms/Scalar/LoopIdiomRecognize.cpp
@@ -30,7 +30,6 @@
// the loop. This would handle things like:
// void foo(_Complex float *P)
// for (i) { __real__(*P) = 0; __imag__(*P) = 0; }
-// this is also "Example 2" from http://blog.regehr.org/archives/320
//
// This could recognize common matrix multiplies and dot product idioms and
// replace them with calls to BLAS (if linked in??).
@@ -46,6 +45,7 @@
#include "llvm/Analysis/ScalarEvolutionExpander.h"
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/Target/TargetData.h"
+#include "llvm/Target/TargetLibraryInfo.h"
#include "llvm/Transforms/Utils/Local.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/IRBuilder.h"
@@ -62,6 +62,7 @@
const TargetData *TD;
DominatorTree *DT;
ScalarEvolution *SE;
+ TargetLibraryInfo *TLI;
public:
static char ID;
explicit LoopIdiomRecognize() : LoopPass(ID) {
@@ -101,6 +102,7 @@
AU.addPreserved<ScalarEvolution>();
AU.addPreserved<DominatorTree>();
AU.addRequired<DominatorTree>();
+ AU.addRequired<TargetLibraryInfo>();
}
};
}
@@ -113,6 +115,7 @@
INITIALIZE_PASS_DEPENDENCY(LoopSimplify)
INITIALIZE_PASS_DEPENDENCY(LCSSA)
INITIALIZE_PASS_DEPENDENCY(ScalarEvolution)
+INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfo)
INITIALIZE_AG_DEPENDENCY(AliasAnalysis)
INITIALIZE_PASS_END(LoopIdiomRecognize, "loop-idiom", "Recognize loop idioms",
false, false)
@@ -175,6 +178,7 @@
DT = &getAnalysis<DominatorTree>();
LoopInfo &LI = getAnalysis<LoopInfo>();
+ TLI = &getAnalysis<TargetLibraryInfo>();
SmallVector<BasicBlock*, 8> ExitBlocks;
CurLoop->getUniqueExitBlocks(ExitBlocks);
@@ -302,6 +306,10 @@
// We can only handle non-volatile memsets with a constant size.
if (MSI->isVolatile() || !isa<ConstantInt>(MSI->getLength())) return false;
+ // If we're not allowed to hack on memset, we fail.
+ if (!TLI->has(LibFunc::memset))
+ return false;
+
Value *Pointer = MSI->getDest();
// See if the pointer expression is an AddRec like {base,+,1} on the current
@@ -371,6 +379,11 @@
unsigned StoreAlignment, Value *SplatValue,
Instruction *TheStore,
const SCEVAddRecExpr *Ev, const SCEV *BECount) {
+ // If we're not allowed to form memset, we fail.
+ if (!TLI->has(LibFunc::memset))
+ return false;
+
+
// Verify that the stored value is loop invariant. If not, we can't promote
// the memset.
if (!CurLoop->isLoopInvariant(SplatValue))
@@ -435,6 +448,10 @@
const SCEVAddRecExpr *StoreEv,
const SCEVAddRecExpr *LoadEv,
const SCEV *BECount) {
+ // If we're not allowed to form memcpy, we fail.
+ if (!TLI->has(LibFunc::memcpy))
+ return false;
+
LoadInst *LI = cast<LoadInst>(SI->getValueOperand());
// Okay, we have a strided store "p[i]" of a loaded value. We can turn