llvm/test/Transforms/IndVarSimplify/loop_evaluate10.ll
Andrew Trick 79f0bfcc20 Fix SCEV overly optimistic back edge taken count for multi-exit loops.
Fixes PR11375: Different results for 'clang++ huh.cpp'...


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144746 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-16 00:52:40 +00:00

54 lines
1.8 KiB
LLVM

; RUN: opt < %s -indvars -S \
; RUN: | grep {%b.1 = phi i32 \\\[ 2, %bb \\\], \\\[ 1, %bb2 \\\]}
;
; This loop has multiple exits, and the value of %b1 depends on which
; exit is taken. Indvars should correctly compute the exit values.
;
; XFAIL: *
; Indvars does not currently replace loop invariant values unless all
; loop exits have the same exit value. We could handle some cases,
; such as this, by making getSCEVAtScope() sensitive to a particular
; loop exit. See PR11388.
target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128"
target triple = "x86_64-pc-linux-gnu"
%struct..0anon = type <{ i8, [3 x i8] }>
define i32 @main() nounwind {
entry:
br label %bb2
bb2: ; preds = %bb, %entry
%sdata.0 = phi i32 [ 1, %entry ], [ %ins10, %bb ] ; <i32> [#uses=2]
%b.0 = phi i32 [ 0, %entry ], [ %t0, %bb ] ; <i32> [#uses=2]
%tmp6 = trunc i32 %sdata.0 to i8 ; <i8> [#uses=2]
%t2 = and i8 %tmp6, 1 ; <i8> [#uses=1]
%t3 = icmp eq i8 %t2, 0 ; <i1> [#uses=1]
%t4 = xor i8 %tmp6, 1 ; <i8> [#uses=1]
%tmp8 = zext i8 %t4 to i32 ; <i32> [#uses=1]
%mask9 = and i32 %sdata.0, -256 ; <i32> [#uses=1]
%ins10 = or i32 %tmp8, %mask9 ; <i32> [#uses=1]
br i1 %t3, label %bb3, label %bb
bb: ; preds = %bb2
%t0 = add i32 %b.0, 1 ; <i32> [#uses=3]
%t1 = icmp sgt i32 %t0, 100 ; <i1> [#uses=1]
br i1 %t1, label %bb3, label %bb2
bb3: ; preds = %bb, %bb2
%b.1 = phi i32 [ %t0, %bb ], [ %b.0, %bb2 ] ; <i32> [#uses=1]
%t5 = icmp eq i32 %b.1, 1 ; <i1> [#uses=1]
br i1 %t5, label %bb5, label %bb4
bb4: ; preds = %bb3
tail call void @abort() noreturn nounwind
unreachable
bb5: ; preds = %bb3
ret i32 0
}
declare void @llvm.memset.i64(i8* nocapture, i8, i64, i32) nounwind
declare void @abort() noreturn nounwind