Don't attempt to simplify an non-affine IV expression if it can't

be simplified to a loop-invariant value. This fixes PR4315.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72798 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 43 insertions, 0 deletions

diff --git a/test/Transforms/IndVarSimplify/variable-stride-ivs.ll b/test/Transforms/IndVarSimplify/variable-stride-ivs-0.ll
index 759ba8e..759ba8e 100644
--- a/test/Transforms/IndVarSimplify/variable-stride-ivs.ll
+++ b/test/Transforms/IndVarSimplify/variable-stride-ivs-0.ll
diff --git a/test/Transforms/IndVarSimplify/variable-stride-ivs-1.ll b/test/Transforms/IndVarSimplify/variable-stride-ivs-1.ll
new file mode 100644
index 0000000..075e899
--- /dev/null
+++ b/test/Transforms/IndVarSimplify/variable-stride-ivs-1.ll
@@ -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
+}