[llvm] r251393 - [ScalarEvolutionExpander] Properly insert no-op casts + EH Pads
David Majnemer via llvm-commits
llvm-commits at lists.llvm.org
Tue Oct 27 00:36:42 PDT 2015
Author: majnemer
Date: Tue Oct 27 02:36:42 2015
New Revision: 251393
URL: http://llvm.org/viewvc/llvm-project?rev=251393&view=rev
Log:
[ScalarEvolutionExpander] Properly insert no-op casts + EH Pads
We want to insert no-op casts as close as possible to the def. This is
tricky when the cast is of a PHI node and the BasicBlocks between the
def and the use cannot hold any instructions. Iteratively walk EH pads
until we hit a non-EH pad.
This fixes PR25326.
Added:
llvm/trunk/test/Transforms/LoopStrengthReduce/funclet.ll
Modified:
llvm/trunk/lib/Analysis/ScalarEvolutionExpander.cpp
Modified: llvm/trunk/lib/Analysis/ScalarEvolutionExpander.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/ScalarEvolutionExpander.cpp?rev=251393&r1=251392&r2=251393&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/ScalarEvolutionExpander.cpp (original)
+++ llvm/trunk/lib/Analysis/ScalarEvolutionExpander.cpp Tue Oct 27 02:36:42 2015
@@ -86,6 +86,41 @@ Value *SCEVExpander::ReuseOrCreateCast(V
return Ret;
}
+static BasicBlock::iterator findInsertPointAfter(Instruction *I,
+ DominatorTree &DT,
+ BasicBlock *MustDominate) {
+ BasicBlock::iterator IP = ++I->getIterator();
+ if (auto *II = dyn_cast<InvokeInst>(I))
+ IP = II->getNormalDest()->begin();
+ if (auto *CPI = dyn_cast<CatchPadInst>(I))
+ IP = CPI->getNormalDest()->begin();
+
+ while (isa<PHINode>(IP))
+ ++IP;
+
+ while (IP->isEHPad()) {
+ if (isa<LandingPadInst>(IP) || isa<CleanupPadInst>(IP)) {
+ ++IP;
+ } else if (auto *TPI = dyn_cast<TerminatePadInst>(IP)) {
+ IP = TPI->getUnwindDest()->getFirstNonPHI();
+ } else if (auto *CEPI = dyn_cast<CatchEndPadInst>(IP)) {
+ IP = CEPI->getUnwindDest()->getFirstNonPHI();
+ } else if (auto *CEPI = dyn_cast<CleanupEndPadInst>(IP)) {
+ IP = CEPI->getUnwindDest()->getFirstNonPHI();
+ } else if (auto *CPI = dyn_cast<CatchPadInst>(IP)) {
+ BasicBlock *NormalDest = CPI->getNormalDest();
+ if (NormalDest == MustDominate || DT.dominates(NormalDest, MustDominate))
+ IP = NormalDest->getFirstNonPHI();
+ else
+ IP = CPI->getUnwindDest()->getFirstNonPHI();
+ } else {
+ llvm_unreachable("unexpected eh pad!");
+ }
+ }
+
+ return IP;
+}
+
/// InsertNoopCastOfTo - Insert a cast of V to the specified type,
/// which must be possible with a noop cast, doing what we can to share
/// the casts.
@@ -135,21 +170,15 @@ Value *SCEVExpander::InsertNoopCastOfTo(
while ((isa<BitCastInst>(IP) &&
isa<Argument>(cast<BitCastInst>(IP)->getOperand(0)) &&
cast<BitCastInst>(IP)->getOperand(0) != A) ||
- isa<DbgInfoIntrinsic>(IP) ||
- isa<LandingPadInst>(IP))
+ isa<DbgInfoIntrinsic>(IP))
++IP;
return ReuseOrCreateCast(A, Ty, Op, IP);
}
// Cast the instruction immediately after the instruction.
Instruction *I = cast<Instruction>(V);
- BasicBlock::iterator IP = ++I->getIterator();
- if (InvokeInst *II = dyn_cast<InvokeInst>(I))
- IP = II->getNormalDest()->begin();
- if (CatchPadInst *CPI = dyn_cast<CatchPadInst>(I))
- IP = CPI->getNormalDest()->begin();
- while (isa<PHINode>(IP) || isa<LandingPadInst>(IP))
- ++IP;
+ BasicBlock::iterator IP =
+ findInsertPointAfter(I, SE.DT, Builder.GetInsertBlock());
return ReuseOrCreateCast(I, Ty, Op, IP);
}
@@ -1394,12 +1423,8 @@ Value *SCEVExpander::visitAddRecExpr(con
NewOps[i] = SE.getAnyExtendExpr(S->op_begin()[i], CanonicalIV->getType());
Value *V = expand(SE.getAddRecExpr(NewOps, S->getLoop(),
S->getNoWrapFlags(SCEV::FlagNW)));
- BasicBlock::iterator NewInsertPt =
- std::next(BasicBlock::iterator(cast<Instruction>(V)));
- BuilderType::InsertPointGuard Guard(Builder);
- while (isa<PHINode>(NewInsertPt) || isa<DbgInfoIntrinsic>(NewInsertPt) ||
- isa<LandingPadInst>(NewInsertPt))
- ++NewInsertPt;
+ BasicBlock::iterator NewInsertPt = findInsertPointAfter(
+ cast<Instruction>(V), SE.DT, Builder.GetInsertBlock());
V = expandCodeFor(SE.getTruncateExpr(SE.getUnknown(V), Ty), nullptr,
&*NewInsertPt);
return V;
Added: llvm/trunk/test/Transforms/LoopStrengthReduce/funclet.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LoopStrengthReduce/funclet.ll?rev=251393&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/LoopStrengthReduce/funclet.ll (added)
+++ llvm/trunk/test/Transforms/LoopStrengthReduce/funclet.ll Tue Oct 27 02:36:42 2015
@@ -0,0 +1,148 @@
+; RUN: opt < %s -loop-reduce -S | FileCheck %s
+
+target datalayout = "e-m:x-p:32:32-i64:64-f80:32-n8:16:32-a:0:32-S32"
+target triple = "i686-pc-windows-msvc"
+
+declare i32 @_except_handler3(...)
+
+declare void @reserve()
+
+define void @f() personality i32 (...)* @_except_handler3 {
+entry:
+ br label %throw
+
+throw: ; preds = %throw, %entry
+ %tmp96 = getelementptr inbounds i8, i8* undef, i32 1
+ invoke void @reserve()
+ to label %throw unwind label %pad
+
+pad: ; preds = %throw
+ %phi2 = phi i8* [ %tmp96, %throw ]
+ terminatepad [] unwind label %blah
+
+blah:
+ catchpad [] to label %unreachable unwind label %blah3
+
+unreachable:
+ unreachable
+
+blah3:
+ catchendpad unwind label %blah2
+
+blah2:
+ %cleanuppadi4.i.i.i = cleanuppad []
+ br label %loop_body
+
+loop_body: ; preds = %iter, %pad
+ %tmp99 = phi i8* [ %tmp101, %iter ], [ %phi2, %blah2 ]
+ %tmp100 = icmp eq i8* %tmp99, undef
+ br i1 %tmp100, label %unwind_out, label %iter
+
+iter: ; preds = %loop_body
+ %tmp101 = getelementptr inbounds i8, i8* %tmp99, i32 1
+ br i1 undef, label %unwind_out, label %loop_body
+
+unwind_out: ; preds = %iter, %loop_body
+ cleanupret %cleanuppadi4.i.i.i unwind to caller
+}
+
+; CHECK-LABEL: define void @f(
+; CHECK: cleanuppad []
+; CHECK-NEXT: ptrtoint i8* %phi2 to i32
+
+define void @g() personality i32 (...)* @_except_handler3 {
+entry:
+ br label %throw
+
+throw: ; preds = %throw, %entry
+ %tmp96 = getelementptr inbounds i8, i8* undef, i32 1
+ invoke void @reserve()
+ to label %throw unwind label %pad
+
+pad:
+ %phi2 = phi i8* [ %tmp96, %throw ]
+ catchpad [] to label %unreachable unwind label %blah
+
+unreachable:
+ unreachable
+
+blah:
+ %catchpad = catchpad [] to label %loop_body unwind label %blah3
+
+
+blah3:
+ catchendpad unwind to caller ;label %blah2
+
+unwind_out:
+ catchret %catchpad to label %leave
+
+leave:
+ ret void
+
+loop_body: ; preds = %iter, %pad
+ %tmp99 = phi i8* [ %tmp101, %iter ], [ %phi2, %blah ]
+ %tmp100 = icmp eq i8* %tmp99, undef
+ br i1 %tmp100, label %unwind_out, label %iter
+
+iter: ; preds = %loop_body
+ %tmp101 = getelementptr inbounds i8, i8* %tmp99, i32 1
+ br i1 undef, label %unwind_out, label %loop_body
+}
+
+; CHECK-LABEL: define void @g(
+; CHECK: blah:
+; CHECK-NEXT: catchpad []
+; CHECK-NEXT: to label %loop_body.preheader
+
+; CHECK: loop_body.preheader:
+; CHECK-NEXT: ptrtoint i8* %phi2 to i32
+
+
+define void @h() personality i32 (...)* @_except_handler3 {
+entry:
+ br label %throw
+
+throw: ; preds = %throw, %entry
+ %tmp96 = getelementptr inbounds i8, i8* undef, i32 1
+ invoke void @reserve()
+ to label %throw unwind label %pad
+
+pad:
+ catchpad [] to label %unreachable unwind label %blug
+
+unreachable:
+ unreachable
+
+blug:
+ %phi2 = phi i8* [ %tmp96, %pad ]
+ %catchpad = catchpad [] to label %blah2 unwind label %blah3
+
+blah2:
+ br label %loop_body
+
+blah3:
+ catchendpad unwind to caller ;label %blah2
+
+unwind_out:
+ catchret %catchpad to label %leave
+
+leave:
+ ret void
+
+loop_body: ; preds = %iter, %pad
+ %tmp99 = phi i8* [ %tmp101, %iter ], [ %phi2, %blah2 ]
+ %tmp100 = icmp eq i8* %tmp99, undef
+ br i1 %tmp100, label %unwind_out, label %iter
+
+iter: ; preds = %loop_body
+ %tmp101 = getelementptr inbounds i8, i8* %tmp99, i32 1
+ br i1 undef, label %unwind_out, label %loop_body
+}
+
+; CHECK-LABEL: define void @h(
+; CHECK: blug:
+; CHECK: catchpad []
+; CHECK-NEXT: to label %blah2
+
+; CHECK: blah2:
+; CHECK-NEXT: ptrtoint i8* %phi2 to i32
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