llvm-6502/test/Transforms/LoopUnroll/2011-08-08-PhiUpdate.ll
Andrew Trick b1eede1281 Fix the LoopUnroller to handle nontrivial loops and partial unrolling.
These are not individual bug fixes. I had to rewrite a good chunk of
the unroller to make it sane. I think it was getting lucky on trivial
completely unrolled loops with no early exits. I included some fairly
simple unit tests for partial unrolling. I didn't do much stress
testing, so it may not be perfect, but should be usable now.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137190 91177308-0d34-0410-b5e6-96231b3b80d8
2011-08-10 00:28:10 +00:00

101 lines
3.8 KiB
LLVM

; RUN: opt < %s -loop-unroll -S -unroll-count=4 | FileCheck %s
; Test phi update after partial unroll.
declare i1 @check() nounwind
; CHECK: @test
; CHECK: if.else:
; CHECK: if.then.loopexit
; CHECK: %sub5.lcssa = phi i32 [ %sub{{.*}}, %if.else{{.*}} ], [ %sub{{.*}}, %if.else{{.*}} ], [ %sub{{.*}}, %if.else{{.*}} ], [ %sub{{.*}}, %if.else{{.*}} ]
; CHECK: if.else.3
define void @test1(i32 %i, i32 %j) nounwind uwtable ssp {
entry:
%cond1 = call zeroext i1 @check()
br i1 %cond1, label %if.then, label %if.else.lr.ph
if.else.lr.ph: ; preds = %entry
br label %if.else
if.else: ; preds = %if.else, %if.else.lr.ph
%sub = phi i32 [ %i, %if.else.lr.ph ], [ %sub5, %if.else ]
%sub5 = sub i32 %sub, %j
%cond2 = call zeroext i1 @check()
br i1 %cond2, label %if.then, label %if.else
if.then: ; preds = %if.else, %entry
%i.tr = phi i32 [ %i, %entry ], [ %sub5, %if.else ]
ret void
}
; PR7318: assertion failure after doing a simple loop unroll
;
; CHECK: @test2
; CHECK: bb1.bb2_crit_edge:
; CHECK: %.lcssa = phi i32 [ %{{[2468]}}, %bb1{{.*}} ], [ %{{[2468]}}, %bb1{{.*}} ], [ %{{[2468]}}, %bb1{{.*}} ], [ %{{[2468]}}, %bb1{{.*}} ]
; CHECK: bb1.3:
define i32 @test2(i32* nocapture %p, i32 %n) nounwind readonly {
entry:
%0 = icmp sgt i32 %n, 0 ; <i1> [#uses=1]
br i1 %0, label %bb.nph, label %bb2
bb.nph: ; preds = %entry
%tmp = zext i32 %n to i64 ; <i64> [#uses=1]
br label %bb
bb: ; preds = %bb.nph, %bb1
%indvar = phi i64 [ 0, %bb.nph ], [ %indvar.next, %bb1 ] ; <i64> [#uses=2]
%s.01 = phi i32 [ 0, %bb.nph ], [ %2, %bb1 ] ; <i32> [#uses=1]
%scevgep = getelementptr i32* %p, i64 %indvar ; <i32*> [#uses=1]
%1 = load i32* %scevgep, align 1 ; <i32> [#uses=1]
%2 = add nsw i32 %1, %s.01 ; <i32> [#uses=2]
br label %bb1
bb1: ; preds = %bb
%indvar.next = add i64 %indvar, 1 ; <i64> [#uses=2]
%exitcond = icmp ne i64 %indvar.next, %tmp ; <i1> [#uses=1]
br i1 %exitcond, label %bb, label %bb1.bb2_crit_edge
bb1.bb2_crit_edge: ; preds = %bb1
%.lcssa = phi i32 [ %2, %bb1 ] ; <i32> [#uses=1]
br label %bb2
bb2: ; preds = %bb1.bb2_crit_edge, %entry
%s.0.lcssa = phi i32 [ %.lcssa, %bb1.bb2_crit_edge ], [ 0, %entry ] ; <i32> [#uses=1]
ret i32 %s.0.lcssa
}
; Check phi update for loop with an early-exit.
;
; CHECK: @test3
; CHECK: return.loopexit:
; CHECK: %tmp7.i.lcssa = phi i32 [ %tmp7.i{{.*}}, %land.lhs.true{{.*}} ], [ %tmp7.i{{.*}}, %land.lhs.true{{.*}} ], [ %tmp7.i{{.*}}, %land.lhs.true{{.*}} ], [ %tmp7.i{{.*}}, %land.lhs.true{{.*}} ]
; CHECK: exit.3:
define i32 @test3() nounwind uwtable ssp align 2 {
entry:
br i1 undef, label %return, label %if.end
if.end: ; preds = %entry
br label %do.body
do.body: ; preds = %do.cond, %if.end
br i1 undef, label %exit, label %do.cond
exit: ; preds = %do.body
%tmp7.i = load i32* undef, align 8
br i1 undef, label %do.cond, label %land.lhs.true
land.lhs.true: ; preds = %exit
br i1 undef, label %return, label %do.cond
do.cond: ; preds = %land.lhs.true, %exit, %do.body
br i1 undef, label %do.end, label %do.body
do.end: ; preds = %do.cond
br label %return
return: ; preds = %do.end, %land.lhs.true, %entry
%retval.0 = phi i32 [ 0, %do.end ], [ 0, %entry ], [ %tmp7.i, %land.lhs.true ]
ret i32 %retval.0
}