llvm-6502/test/Transforms/IndVarSimplify/widen-loop-comp.ll
Sanjoy Das de87c9165a Teach ScalarEvolution to sharpen range information.
If x is known to have the range [a, b), in a loop predicated by (icmp
ne x, a) its range can be sharpened to [a + 1, b).  Get
ScalarEvolution and hence IndVars to exploit this fact.

This change triggers an optimization to widen-loop-comp.ll, so it had
to be edited to get it to pass.

This change was originally landed in r219834 but had a bug and broke
ASan. It was reverted in r219878, and is now being re-landed after
fixing the original bug.

phabricator: http://reviews.llvm.org/D5639
reviewed by: atrick



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221839 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-13 00:00:58 +00:00

192 lines
4.8 KiB
LLVM

; RUN: opt < %s -indvars -S | FileCheck %s
target triple = "aarch64--linux-gnu"
; Check the loop exit i32 compare instruction and operand are widened to i64
; instead of truncating IV before its use in the i32 compare instruction.
@idx = common global i32 0, align 4
@e = common global i32 0, align 4
@ptr = common global i32* null, align 8
; CHECK-LABEL: @test1
; CHECK: for.body.lr.ph:
; CHECK: sext i32
; CHECK: for.cond:
; CHECK: icmp slt i64
; CHECK: for.body:
; CHECK: phi i64
define i32 @test1() {
entry:
store i32 -1, i32* @idx, align 4
%0 = load i32* @e, align 4
%cmp4 = icmp slt i32 %0, 0
br i1 %cmp4, label %for.end.loopexit, label %for.body.lr.ph
for.body.lr.ph:
%1 = load i32** @ptr, align 8
%2 = load i32* @e, align 4
br label %for.body
for.cond:
%inc = add nsw i32 %i.05, 1
%cmp = icmp slt i32 %i.05, %2
br i1 %cmp, label %for.body, label %for.cond.for.end.loopexit_crit_edge
for.body:
%i.05 = phi i32 [ 0, %for.body.lr.ph ], [ %inc, %for.cond ]
%idxprom = sext i32 %i.05 to i64
%arrayidx = getelementptr inbounds i32* %1, i64 %idxprom
%3 = load i32* %arrayidx, align 4
%tobool = icmp eq i32 %3, 0
br i1 %tobool, label %if.then, label %for.cond
if.then:
%i.05.lcssa = phi i32 [ %i.05, %for.body ]
store i32 %i.05.lcssa, i32* @idx, align 4
br label %for.end
for.cond.for.end.loopexit_crit_edge:
br label %for.end.loopexit
for.end.loopexit:
br label %for.end
for.end:
%4 = load i32* @idx, align 4
ret i32 %4
}
; CHECK-LABEL: @test2
; CHECK: for.body4.us
; CHECK: %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
; CHECK: %cmp2.us = icmp slt i64
; CHECK-NOT: %2 = trunc i64 %indvars.iv.next to i32
; CHECK-NOT: %cmp2.us = icmp slt i32
define void @test2([8 x i8]* %a, i8* %b, i8 %limit) {
entry:
%conv = zext i8 %limit to i32
br i1 undef, label %for.cond1.preheader, label %for.cond1.preheader.us
for.cond1.preheader.us:
%storemerge5.us = phi i32 [ 0, %entry ], [ %inc14.us, %for.inc13.us ]
br i1 true, label %for.body4.lr.ph.us, label %for.inc13.us
for.inc13.us:
%inc14.us = add nsw i32 %storemerge5.us, 1
%cmp.us = icmp slt i32 %inc14.us, 4
br i1 %cmp.us, label %for.cond1.preheader.us, label %for.end
for.body4.us:
%storemerge14.us = phi i32 [ 0, %for.body4.lr.ph.us ], [ %inc.us, %for.body4.us ]
%idxprom.us = sext i32 %storemerge14.us to i64
%arrayidx6.us = getelementptr inbounds [8 x i8]* %a, i64 %idxprom5.us, i64 %idxprom.us
%0 = load i8* %arrayidx6.us, align 1
%idxprom7.us = zext i8 %0 to i64
%arrayidx8.us = getelementptr inbounds i8* %b, i64 %idxprom7.us
%1 = load i8* %arrayidx8.us, align 1
store i8 %1, i8* %arrayidx6.us, align 1
%inc.us = add nsw i32 %storemerge14.us, 1
%cmp2.us = icmp slt i32 %inc.us, %conv
br i1 %cmp2.us, label %for.body4.us, label %for.inc13.us
for.body4.lr.ph.us:
%idxprom5.us = sext i32 %storemerge5.us to i64
br label %for.body4.us
for.cond1.preheader:
%storemerge5 = phi i32 [ 0, %entry ], [ %inc14, %for.inc13 ]
br i1 false, label %for.inc13, label %for.inc13
for.inc13:
%inc14 = add nsw i32 %storemerge5, 1
%cmp = icmp slt i32 %inc14, 4
br i1 %cmp, label %for.cond1.preheader, label %for.end
for.end:
ret void
}
; CHECK-LABEL: @test3
; CHECK: sext i32 %b
; CHECK: for.cond:
; CHECK: phi i64
; CHECK: icmp slt i64
define i32 @test3(i32* %a, i32 %b) {
entry:
br label %for.cond
for.cond:
%sum.0 = phi i32 [ 0, %entry ], [ %add, %for.body ]
%i.0 = phi i32 [ 0, %entry ], [ %inc, %for.body ]
%cmp = icmp slt i32 %i.0, %b
br i1 %cmp, label %for.body, label %for.end
for.body:
%idxprom = sext i32 %i.0 to i64
%arrayidx = getelementptr inbounds i32* %a, i64 %idxprom
%0 = load i32* %arrayidx, align 4
%add = add nsw i32 %sum.0, %0
%inc = add nsw i32 %i.0, 1
br label %for.cond
for.end:
ret i32 %sum.0
}
declare i32 @fn1(i8 signext)
; PR21030
; CHECK-LABEL: @test4
; CHECK: for.body:
; CHECK: phi i32
; CHECK: icmp sgt i8
define i32 @test4(i32 %a) {
entry:
br label %for.body
for.body:
%c.07 = phi i8 [ -3, %entry ], [ %dec, %for.body ]
%conv6 = zext i8 %c.07 to i32
%or = or i32 %a, %conv6
%conv3 = trunc i32 %or to i8
%call = call i32 @fn1(i8 signext %conv3)
%dec = add i8 %c.07, -1
%cmp = icmp sgt i8 %dec, -14
br i1 %cmp, label %for.body, label %for.end
for.end:
ret i32 0
}
; CHECK-LABEL: @test5
; CHECK: zext i32 %b
; CHECK: for.cond:
; CHECK: phi i64
; CHECK: icmp ule i64
define i32 @test5(i32* %a, i32 %b) {
entry:
br label %for.cond
for.cond:
%sum.0 = phi i32 [ 0, %entry ], [ %add, %for.body ]
%i.0 = phi i32 [ 0, %entry ], [ %inc, %for.body ]
%cmp = icmp ule i32 %i.0, %b
br i1 %cmp, label %for.body, label %for.end
for.body:
%idxprom = zext i32 %i.0 to i64
%arrayidx = getelementptr inbounds i32* %a, i64 %idxprom
%0 = load i32* %arrayidx, align 4
%add = add nsw i32 %sum.0, %0
%inc = add nsw i32 %i.0, 1
br label %for.cond
for.end:
ret i32 %sum.0
}