[llvm-commits] [llvm] r72798 - in /llvm/trunk: lib/Transforms/Scalar/IndVarSimplify.cpp test/Transforms/IndVarSimplify/variable-stride-ivs-0.ll test/Transforms/IndVarSimplify/variable-stride-ivs-1.ll test/Transforms/IndVarSimplify/variable-stride-ivs.ll
Dan Gohman
gohman at apple.com
Wed Jun 3 12:11:31 PDT 2009
Author: djg
Date: Wed Jun 3 14:11:31 2009
New Revision: 72798
URL: http://llvm.org/viewvc/llvm-project?rev=72798&view=rev
Log:
Don't attempt to simplify an non-affine IV expression if it can't
be simplified to a loop-invariant value. This fixes PR4315.
Added:
llvm/trunk/test/Transforms/IndVarSimplify/variable-stride-ivs-0.ll (props changed)
- copied unchanged from r72786, llvm/trunk/test/Transforms/IndVarSimplify/variable-stride-ivs.ll
llvm/trunk/test/Transforms/IndVarSimplify/variable-stride-ivs-1.ll
Removed:
llvm/trunk/test/Transforms/IndVarSimplify/variable-stride-ivs.ll
Modified:
llvm/trunk/lib/Transforms/Scalar/IndVarSimplify.cpp
Modified: llvm/trunk/lib/Transforms/Scalar/IndVarSimplify.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/IndVarSimplify.cpp?rev=72798&r1=72797&r2=72798&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/IndVarSimplify.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/IndVarSimplify.cpp Wed Jun 3 14:11:31 2009
@@ -465,17 +465,6 @@
// Compute the final addrec to expand into code.
SCEVHandle AR = IU->getReplacementExpr(*UI);
- // FIXME: It is an extremely bad idea to indvar substitute anything more
- // complex than affine induction variables. Doing so will put expensive
- // polynomial evaluations inside of the loop, and the str reduction pass
- // currently can only reduce affine polynomials. For now just disable
- // indvar subst on anything more complex than an affine addrec, unless
- // it can be expanded to a trivial value.
- if (!Stride->isLoopInvariant(L) &&
- !isa<SCEVConstant>(AR) &&
- L->contains(User->getParent()))
- continue;
-
Value *NewVal = 0;
if (AR->isLoopInvariant(L)) {
BasicBlock::iterator I = Rewriter.getInsertionPoint();
@@ -487,6 +476,15 @@
Rewriter.setInsertionPoint(I);
++NumReplaced;
} else {
+ // FIXME: It is an extremely bad idea to indvar substitute anything more
+ // complex than affine induction variables. Doing so will put expensive
+ // polynomial evaluations inside of the loop, and the str reduction pass
+ // currently can only reduce affine polynomials. For now just disable
+ // indvar subst on anything more complex than an affine addrec, unless
+ // it can be expanded to a trivial value.
+ if (!Stride->isLoopInvariant(L))
+ continue;
+
const Type *IVTy = Offset->getType();
const Type *UseTy = Op->getType();
@@ -520,7 +518,7 @@
// induction variable, still in the canonical induction variable's
// type, so that all expanded arithmetic is done in the same type.
SCEVHandle NewAR = SE->getAddRecExpr(SE->getIntegerSCEV(0, LargestType),
- PromotedStride, L);
+ PromotedStride, L);
// Add the PromotedOffset as a separate step, because it may not be
// loop-invariant.
NewAR = SE->getAddExpr(NewAR, PromotedOffset);
Propchange: llvm/trunk/test/Transforms/IndVarSimplify/variable-stride-ivs-0.ll
------------------------------------------------------------------------------
cvs2svn:cvs-rev = 1.4
Propchange: llvm/trunk/test/Transforms/IndVarSimplify/variable-stride-ivs-0.ll
------------------------------------------------------------------------------
svn:eol-style = native
Propchange: llvm/trunk/test/Transforms/IndVarSimplify/variable-stride-ivs-0.ll
------------------------------------------------------------------------------
svn:keywords = Author Date Id Revision
Propchange: llvm/trunk/test/Transforms/IndVarSimplify/variable-stride-ivs-0.ll
------------------------------------------------------------------------------
svn:mergeinfo =
Added: llvm/trunk/test/Transforms/IndVarSimplify/variable-stride-ivs-1.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/IndVarSimplify/variable-stride-ivs-1.ll?rev=72798&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/IndVarSimplify/variable-stride-ivs-1.ll (added)
+++ llvm/trunk/test/Transforms/IndVarSimplify/variable-stride-ivs-1.ll Wed Jun 3 14:11:31 2009
@@ -0,0 +1,43 @@
+; RUN: llvm-as < %s | opt -indvars
+; PR4315
+
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"
+target triple = "x86_64-undermydesk-freebsd8.0"
+ %struct.mbuf = type <{ %struct.mbuf*, i8*, i32, i8, i8, i8, i8 }>
+
+define i32 @crash(%struct.mbuf* %m) nounwind {
+entry:
+ br label %for.cond
+
+for.cond: ; preds = %if.end, %entry
+ %i.0 = phi i32 [ 0, %entry ], [ %inc, %if.end ] ; <i32> [#uses=3]
+ %chksum.0 = phi i8 [ 0, %entry ], [ %conv3, %if.end ] ; <i8> [#uses=3]
+ %cmp = icmp slt i32 %i.0, 1 ; <i1> [#uses=1]
+ br i1 %cmp, label %for.body, label %do.body
+
+for.body: ; preds = %for.cond
+ br i1 undef, label %if.end, label %do.body
+
+if.end: ; preds = %for.body
+ %i.02 = trunc i32 %i.0 to i8 ; <i8> [#uses=1]
+ %conv3 = add i8 %chksum.0, %i.02 ; <i8> [#uses=1]
+ %inc = add i32 %i.0, 1 ; <i32> [#uses=1]
+ br label %for.cond
+
+do.body: ; preds = %do.cond, %for.body, %for.cond
+ %chksum.2 = phi i8 [ undef, %do.cond ], [ %chksum.0, %for.body ], [ %chksum.0, %for.cond ] ; <i8> [#uses=1]
+ br i1 undef, label %do.cond, label %bb.nph
+
+bb.nph: ; preds = %do.body
+ br label %while.body
+
+while.body: ; preds = %while.body, %bb.nph
+ %chksum.13 = phi i8 [ undef, %while.body ], [ %chksum.2, %bb.nph ] ; <i8> [#uses=0]
+ br i1 undef, label %do.cond, label %while.body
+
+do.cond: ; preds = %while.body, %do.body
+ br i1 false, label %do.end, label %do.body
+
+do.end: ; preds = %do.cond
+ ret i32 0
+}
Removed: llvm/trunk/test/Transforms/IndVarSimplify/variable-stride-ivs.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/IndVarSimplify/variable-stride-ivs.ll?rev=72797&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/IndVarSimplify/variable-stride-ivs.ll (original)
+++ llvm/trunk/test/Transforms/IndVarSimplify/variable-stride-ivs.ll (removed)
@@ -1,43 +0,0 @@
-; RUN: llvm-as < %s | opt -indvars -instcombine | llvm-dis | \
-; RUN: grep {store i32 0}
-; Test that -indvars can reduce variable stride IVs. If it can reduce variable
-; stride iv's, it will make %iv. and %m.0.0 isomorphic to each other without
-; cycles, allowing the tmp.21 subtraction to be eliminated.
-; END.
-
-define void @vnum_test8(i32* %data) {
-entry:
- %tmp.1 = getelementptr i32* %data, i32 3 ; <i32*> [#uses=1]
- %tmp.2 = load i32* %tmp.1 ; <i32> [#uses=2]
- %tmp.4 = getelementptr i32* %data, i32 4 ; <i32*> [#uses=1]
- %tmp.5 = load i32* %tmp.4 ; <i32> [#uses=2]
- %tmp.8 = getelementptr i32* %data, i32 2 ; <i32*> [#uses=1]
- %tmp.9 = load i32* %tmp.8 ; <i32> [#uses=3]
- %tmp.125 = icmp sgt i32 %tmp.2, 0 ; <i1> [#uses=1]
- br i1 %tmp.125, label %no_exit.preheader, label %return
-
-no_exit.preheader: ; preds = %entry
- %tmp.16 = getelementptr i32* %data, i32 %tmp.9 ; <i32*> [#uses=1]
- br label %no_exit
-
-no_exit: ; preds = %no_exit, %no_exit.preheader
- %iv.ui = phi i32 [ 0, %no_exit.preheader ], [ %iv..inc.ui, %no_exit ] ; <i32> [#uses=1]
- %iv. = phi i32 [ %tmp.5, %no_exit.preheader ], [ %iv..inc, %no_exit ] ; <i32> [#uses=2]
- %m.0.0 = phi i32 [ %tmp.5, %no_exit.preheader ], [ %tmp.24, %no_exit ] ; <i32> [#uses=2]
- store i32 2, i32* %tmp.16
- %tmp.21 = sub i32 %m.0.0, %iv. ; <i32> [#uses=1]
- store i32 %tmp.21, i32* %data
- %tmp.24 = add i32 %m.0.0, %tmp.9 ; <i32> [#uses=1]
- %iv..inc = add i32 %tmp.9, %iv. ; <i32> [#uses=1]
- %iv..inc.ui = add i32 %iv.ui, 1 ; <i32> [#uses=2]
- %iv..inc1 = bitcast i32 %iv..inc.ui to i32 ; <i32> [#uses=1]
- %tmp.12 = icmp slt i32 %iv..inc1, %tmp.2 ; <i1> [#uses=1]
- br i1 %tmp.12, label %no_exit, label %return.loopexit
-
-return.loopexit: ; preds = %no_exit
- br label %return
-
-return: ; preds = %return.loopexit, %entry
- ret void
-}
-
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