mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-12-21 00:32:23 +00:00
e62289b98f
When ExactBECount is a constant, use it for MaxBECount. When MaxBECount cannot be computed, replace it with ExactBECount. Fixes PR9424. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127342 91177308-0d34-0410-b5e6-96231b3b80d8
35 lines
1.2 KiB
LLVM
35 lines
1.2 KiB
LLVM
; RUN: opt -indvars %s
|
|
; PR9424: Attempt to use a SCEVCouldNotCompute object!
|
|
; The inner loop computes the Step and Start of the outer loop.
|
|
; Call that Vexit. The outer End value is max(2,Vexit), because
|
|
; the condition "icmp %4 < 2" does not guard the outer loop.
|
|
; SCEV knows that Vexit has range [2,4], so End == Vexit == Start.
|
|
; Now we have ExactBECount == 0. However, MinStart == 2 and MaxEnd == 4.
|
|
; Since the stride is variable and may wrap, we cannot compute
|
|
; MaxBECount. SCEV should override MaxBECount with ExactBECount.
|
|
|
|
define void @bar() nounwind {
|
|
entry:
|
|
%. = select i1 undef, i32 2, i32 1
|
|
br label %"5.preheader"
|
|
|
|
"4": ; preds = %"5.preheader", %"4"
|
|
%0 = phi i32 [ 0, %"5.preheader" ], [ %1, %"4" ]
|
|
%1 = add nsw i32 %0, 1
|
|
%2 = icmp sgt i32 %., %1
|
|
br i1 %2, label %"4", label %"9"
|
|
|
|
"9": ; preds = %"4"
|
|
%3 = add i32 %6, 1
|
|
%4 = add i32 %3, %1
|
|
%5 = icmp slt i32 %4, 2
|
|
br i1 %5, label %"5.preheader", label %return
|
|
|
|
"5.preheader": ; preds = %"9", %entry
|
|
%6 = phi i32 [ 0, %entry ], [ %4, %"9" ]
|
|
br label %"4"
|
|
|
|
return: ; preds = %"9"
|
|
ret void
|
|
}
|