From ccc3e3733b1e92c01b9b764edc9b3f1f28f2dfed Mon Sep 17 00:00:00 2001 From: Zinovy Nis Date: Thu, 2 Oct 2014 13:01:15 +0000 Subject: [BUG][INDVAR] Fix for PR21014: wrong SCEV operands commuting for non-commutative instructions MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit My commit rL216160 introduced a bug PR21014: IndVars widens code 'for (i = ; i < ...; i++) arr[ CONST - i]' into 'for (i = ; i < ...; i++) arr[ i - CONST]' thus inverting index expression. This patch fixes it. Thanks to Jörg Sonnenberger for pointing. Differential Revision: http://reviews.llvm.org/D5576 llvm-svn: 218867 --- llvm/test/Transforms/IndVarSimplify/2011-09-10-widen-nsw.ll | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'llvm/test/Transforms') diff --git a/llvm/test/Transforms/IndVarSimplify/2011-09-10-widen-nsw.ll b/llvm/test/Transforms/IndVarSimplify/2011-09-10-widen-nsw.ll index 477d15251c6..64fef10463f 100644 --- a/llvm/test/Transforms/IndVarSimplify/2011-09-10-widen-nsw.ll +++ b/llvm/test/Transforms/IndVarSimplify/2011-09-10-widen-nsw.ll @@ -19,7 +19,8 @@ for.body153: ; preds = %for.body153, %for.b ; CHECK: add nsw i64 %indvars.iv, 1 ; CHECK: sub nsw i64 %indvars.iv, 2 -; CHECK: mul nsw i64 %indvars.iv, 4 +; CHECK: sub nsw i64 4, %indvars.iv +; CHECK: mul nsw i64 %indvars.iv, 8 for.body170: ; preds = %for.body170, %for.body153 %i2.19 = phi i32 [ %add249, %for.body170 ], [ 0, %for.body153 ] @@ -29,7 +30,10 @@ for.body170: ; preds = %for.body170, %for.b %sub = sub nsw i32 %i2.19, 2 %sub.idxprom = sext i32 %sub to i64 - %mul = mul nsw i32 %i2.19, 4 + %sub.neg = sub nsw i32 4, %i2.19 + %sub.neg.idxprom = sext i32 %sub.neg to i64 + + %mul = mul nsw i32 %i2.19, 8 %mul.idxprom = sext i32 %mul to i64 %add249 = add nsw i32 %i2.19, %shl132 -- cgit v1.2.3