From: Dan Gohman <gohman@apple.com>
Date: Fri, 18 Jun 2010 01:35:11 +0000 (+0000)
Subject: Disable indvars on loops when LoopSimplify form is not available.
X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=a52838285b6dce66821f0b272cb3479af8c3edb2;p=oota-llvm.git

Disable indvars on loops when LoopSimplify form is not available.
This fixes PR7333.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106267 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Transforms/Scalar/IndVarSimplify.cpp b/lib/Transforms/Scalar/IndVarSimplify.cpp
index 36bea679554..84e393f7071 100644
--- a/lib/Transforms/Scalar/IndVarSimplify.cpp
+++ b/lib/Transforms/Scalar/IndVarSimplify.cpp
@@ -467,6 +467,17 @@ void IndVarSimplify::EliminateIVRemainders() {
 }
 
 bool IndVarSimplify::runOnLoop(Loop *L, LPPassManager &LPM) {
+  // If LoopSimplify form is not available, stay out of trouble. Some notes:
+  //  - LSR currently only supports LoopSimplify-form loops. Indvars'
+  //    canonicalization can be a pessimization without LSR to "clean up"
+  //    afterwards.
+  //  - We depend on having a preheader; in particular,
+  //    Loop::getCanonicalInductionVariable only supports loops with preheaders,
+  //    and we're in trouble if we can't find the induction variable even when
+  //    we've manually inserted one.
+  if (!L->isLoopSimplifyForm())
+    return false;
+
   IU = &getAnalysis<IVUsers>();
   LI = &getAnalysis<LoopInfo>();
   SE = &getAnalysis<ScalarEvolution>();
diff --git a/test/Transforms/IndVarSimplify/indirectbr.ll b/test/Transforms/IndVarSimplify/indirectbr.ll
index b4ce153244a..a208ded22ed 100644
--- a/test/Transforms/IndVarSimplify/indirectbr.ll
+++ b/test/Transforms/IndVarSimplify/indirectbr.ll
@@ -1,6 +1,6 @@
 ; RUN: opt < %s -indvars -S -disable-output
-; PR5758
 
+; PR5758
 define zeroext i1 @foo() nounwind {
 entry:
   indirectbr i8* undef, [label %"202", label %"133"]
@@ -20,3 +20,20 @@ entry:
 "202":                                            ; preds = %entry
   ret i1 false
 }
+
+; PR7333
+define void @__atomvec_module__put_vrml_bonds() nounwind {
+bb7.preheader:                                    ; preds = %entry
+  indirectbr i8* undef, [label %bb14, label %bb16]
+
+bb14:                                             ; preds = %bb14, %bb7.preheader
+  br label %bb16
+
+bb16:                                             ; preds = %bb16, %bb14, %bb7.preheader
+  %S.31.0 = phi i64 [ %3, %bb16 ], [ 1, %bb7.preheader ], [ 1, %bb14 ] ; <i64> [#uses=2]
+  %0 = add nsw i64 %S.31.0, -1                    ; <i64> [#uses=1]
+  %1 = getelementptr inbounds [3 x double]* undef, i64 0, i64 %0 ; <double*> [#uses=1]
+  %2 = load double* %1, align 8                   ; <double> [#uses=0]
+  %3 = add nsw i64 %S.31.0, 1                     ; <i64> [#uses=1]
+  br label %bb16
+}