maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity

Make a test actually test what it set out to test. 

This test seems to have largely been relying on asserts being tripped.
It had a very specific and somewhat uninteresting grep of the output,
but it never really did anything to cause SCEV to be preserved across
loop simplify, certainly not explicitly. And a later addition to it
actually added CHECK lines despite the test never running FileCheck.

Now we actually print SCEV before and after loop simplify to make sure
it is *changing* and being *updated*. Which seems to be much more likely
the point of the test.

llvm-svn: 291740
This commit is contained in:
Chandler Carruth 2017-01-12 03:49:07 +00:00
parent 5289662e4a
commit b4d9a310d2
1 changed files with 50 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

61
llvm/test/Transforms/LoopSimplify/preserve-scev.ll
View File

@ -1,14 +1,38 @@
; RUN: opt -S < %s -indvars | opt -analyze -iv-users | grep "%cmp = icmp slt i32" | grep "= {%\.ph,+,1}<%for.cond>"
; PR8079
; RUN: opt -S < %s -analyze -scalar-evolution -loop-simplify -scalar-evolution | FileCheck %s
; Provide legal integer types.
target datalayout = "n8:16:32:64"
; LoopSimplify should invalidate indvars when splitting out the
; inner loop.
@maxStat = external global i32
; LoopSimplify should invalidate SCEV when splitting out the
; inner loop.
;
; First SCEV print:
; CHECK-LABEL: Classifying expressions for: @test
; CHECK: %[[PHI:.*]] = phi i32 [ 0, %entry ], [ %{{.*}}, %if.then5 ], [ %[[PHI]], %if.end ]
; CHECK-LABEL: Determining loop execution counts for: @test
; CHECK: Loop %for.body18: Unpredictable backedge-taken count.
; CHECK: Loop %for.body18: Unpredictable max backedge-taken count.
; CHECK: Loop %for.body18: Unpredictable predicated backedge-taken count.
; CHECK: Loop %for.cond: <multiple exits> Unpredictable backedge-taken count.
; CHECK: Loop %for.cond: Unpredictable max backedge-taken count.
; CHECK: Loop %for.cond: Unpredictable predicated backedge-taken count.
;
; Now simplify the loop, which should cause SCEV to re-compute more precise
; info here in addition to having preheader PHIs. Second SCEV print:
; CHECK-LABEL: Classifying expressions for: @test
; CHECK: phi i32 [ %{{.*}}, %if.then5 ], [ 0, %entry ]
; CHECK-LABEL: Determining loop execution counts for: @test
; CHECK: Loop %for.body18: Unpredictable backedge-taken count.
; CHECK: Loop %for.body18: Unpredictable max backedge-taken count.
; CHECK: Loop %for.body18: Unpredictable predicated backedge-taken count.
; CHECK: Loop %for.cond: <multiple exits> Unpredictable backedge-taken count.
; CHECK: Loop %for.cond: max backedge-taken count is -2147483647
; CHECK: Loop %for.cond: Unpredictable predicated backedge-taken count.
; CHECK: Loop %for.cond.outer: <multiple exits> Unpredictable backedge-taken count.
; CHECK: Loop %for.cond.outer: Unpredictable max backedge-taken count.
; CHECK: Loop %for.cond.outer: Unpredictable predicated backedge-taken count.
define i32 @test() nounwind {
entry:
br label %for.cond
@ -52,12 +76,27 @@ return: ; preds = %for.body18, %for.bo
declare void @foo() nounwind
; Notify SCEV when removing an ExitingBlock.
; CHECK-LABEL: @mergeExit(
; CHECK: while.cond191:
; CHECK: br i1 %or.cond, label %while.body197
; CHECK-NOT: land.rhs:
; CHECK: ret
; Notify SCEV when removing an ExitingBlock. This only changes the
; backedge-taken information.
;
; First SCEV print:
; CHECK-LABEL: Determining loop execution counts for: @mergeExit
; CHECK: Loop %while.cond191: <multiple exits> Unpredictable backedge-taken count.
; CHECK: Loop %while.cond191: max backedge-taken count is -1
; CHECK: Loop %while.cond191: Unpredictable predicated backedge-taken count.
; CHECK: Loop %while.cond191.outer: <multiple exits> Unpredictable backedge-taken count.
; CHECK: Loop %while.cond191.outer: Unpredictable max backedge-taken count.
; CHECK: Loop %while.cond191.outer: Unpredictable predicated backedge-taken count.
;
; After simplifying, the max backedge count is refined.
; Second SCEV print:
; CHECK-LABEL: Determining loop execution counts for: @mergeExit
; CHECK: Loop %while.cond191: <multiple exits> Unpredictable backedge-taken count.
; CHECK: Loop %while.cond191: max backedge-taken count is 0
; CHECK: Loop %while.cond191: Unpredictable predicated backedge-taken count.
; CHECK: Loop %while.cond191.outer: <multiple exits> Unpredictable backedge-taken count.
; CHECK: Loop %while.cond191.outer: Unpredictable max backedge-taken count.
; CHECK: Loop %while.cond191.outer: Unpredictable predicated backedge-taken count.
define void @mergeExit(i32 %MapAttrCount) nounwind uwtable ssp {
entry:
br i1 undef, label %if.then124, label %if.end126