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llvm-mirror/test/Analysis/ScalarEvolution/or-as-add.ll
Eli Friedman c5a8782468 [SCEV] Make SCEV or modeling more aggressive.
Use haveNoCommonBitsSet to figure out whether an "or" instruction
is equivalent to addition. This handles more cases than just
checking for a constant on the RHS.

Differential Revision: https://reviews.llvm.org/D32239

llvm-svn: 300746
2017-04-19 20:19:58 +00:00

39 lines
1.1 KiB
LLVM

; RUN: opt < %s -analyze -scalar-evolution | FileCheck %s
declare void @z(i32)
declare void @z2(i64)
define void @fun(i1 %bool, i32 %x) {
entry:
br label %body
body:
%i = phi i32 [ 0, %entry ], [ %i.next, %body ]
%bottom_zero = mul i32 %i, 2
%a = or i32 %bottom_zero, 1
call void @z(i32 %a)
%bool_ext = zext i1 %bool to i32
%b = or i32 %bool_ext, %bottom_zero
call void @z(i32 %b)
%shifted = lshr i32 %x, 31
%c = or i32 %shifted, %bottom_zero
call void @z(i32 %c)
%i_ext = zext i32 %i to i64
%d = or i64 %i_ext, 4294967296
call void @z2(i64 %d)
%i.next = add i32 %i, 1
%cond = icmp eq i32 %i.next, 10
br i1 %cond, label %exit, label %body
exit:
ret void
}
; CHECK: %a = or i32 %bottom_zero, 1
; CHECK-NEXT: --> {1,+,2}<%body>
; CHECK: %b = or i32 %bool_ext, %bottom_zero
; CHECK-NEXT: --> {(zext i1 %bool to i32),+,2}
; CHECK: %c = or i32 %shifted, %bottom_zero
; CHECK-NEXT: --> {(%x /u -2147483648),+,2}<%body>
; CHECK: %d = or i64 %i_ext, 4294967296
; CHECK-NEXT: --> {4294967296,+,1}<nuw><nsw><%body>