diff options
| author | Max Kazantsev <max.kazantsev@azul.com> | 2018-11-06 02:02:05 +0000 |
|---|---|---|
| committer | Max Kazantsev <max.kazantsev@azul.com> | 2018-11-06 02:02:05 +0000 |
| commit | e059f4452b270bcf75a343effd4ca4e0ed05b518 (patch) | |
| tree | 06c547bb8427d40369e486daa93b57ffe3e19f53 /llvm/test/Analysis/ScalarEvolution | |
| parent | 6c7073f2f8007a6bb1d992eb68a2eaadd7f4529e (diff) | |
| download | bcm5719-llvm-e059f4452b270bcf75a343effd4ca4e0ed05b518.tar.gz bcm5719-llvm-e059f4452b270bcf75a343effd4ca4e0ed05b518.zip | |
Revert "[IndVars] Smart hard uses detection"
This reverts commit 2f425e9c7946b9d74e64ebbfa33c1caa36914402.
It seems that the check that we still should do the transform if we
know the result is constant is missing in this code. So the logic that
has been deleted by this change is still sometimes accidentally useful.
I revert the change to see what can be done about it. The motivating
case is the following:
@Y = global [400 x i16] zeroinitializer, align 1
define i16 @foo() {
entry:
br label %for.body
for.body: ; preds = %entry, %for.body
%i = phi i16 [ 0, %entry ], [ %inc, %for.body ]
%arrayidx = getelementptr inbounds [400 x i16], [400 x i16]* @Y, i16 0, i16 %i
store i16 0, i16* %arrayidx, align 1
%inc = add nuw nsw i16 %i, 1
%cmp = icmp ult i16 %inc, 400
br i1 %cmp, label %for.body, label %for.end
for.end: ; preds = %for.body
%inc.lcssa = phi i16 [ %inc, %for.body ]
ret i16 %inc.lcssa
}
We should be able to figure out that the result is constant, but the patch
breaks it.
Differential Revision: https://reviews.llvm.org/D51584
llvm-svn: 346198
Diffstat (limited to 'llvm/test/Analysis/ScalarEvolution')
| -rw-r--r-- | llvm/test/Analysis/ScalarEvolution/pr28705.ll | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/llvm/test/Analysis/ScalarEvolution/pr28705.ll b/llvm/test/Analysis/ScalarEvolution/pr28705.ll index 9a8487a6c66..8fbc08e3ca6 100644 --- a/llvm/test/Analysis/ScalarEvolution/pr28705.ll +++ b/llvm/test/Analysis/ScalarEvolution/pr28705.ll @@ -1,11 +1,11 @@ ; PR28705 ; RUN: opt < %s -indvars -S | FileCheck %s -; Check IndVarSimplify doesn't replace external use of the induction var -; "%inc.i.i" with "%.sroa.speculated + 1" because it is not profitable. +; Check IndVarSimplify replaces the exitval use of the induction var "%inc.i.i" +; with "%.sroa.speculated + 1". ; ; CHECK-LABEL: @foo( -; CHECK: %[[EXIT:.+]] = phi i32 [ %inc.i.i, %for.body650 ] +; CHECK: %[[EXIT:.+]] = sub i32 %.sroa.speculated, -1 ; CHECK: %DB.sroa.9.0.lcssa = phi i32 [ 1, %entry ], [ %[[EXIT]], %loopexit ] ; define void @foo(i32 %sub.ptr.div.i, i8* %ref.i1174) local_unnamed_addr { |
