llvm/test/Transforms/InstCombine/urem.ll
Sanjay Patel 1d3aecea02 [InstCombine] sub X, sext(bool Y) -> add X, zext(bool Y)
Prefer add/zext because they are better supported in terms of value-tracking.

Note that the backend should be prepared for this IR canonicalization 
(including vector types) after:
https://reviews.llvm.org/rL284015

Differential Revision: https://reviews.llvm.org/D25135


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284241 91177308-0d34-0410-b5e6-96231b3b80d8
2016-10-14 15:24:31 +00:00

51 lines
1.5 KiB
LLVM

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt < %s -instcombine -S | FileCheck %s
define i64 @rem_unsigned(i64 %x1, i64 %y2) {
; CHECK-LABEL: @rem_unsigned(
; CHECK-NEXT: [[R:%.*]] = urem i64 %x1, %y2
; CHECK-NEXT: ret i64 [[R]]
;
%r = udiv i64 %x1, %y2
%r7 = mul i64 %r, %y2
%r8 = sub i64 %x1, %r7
ret i64 %r8
}
; PR28672 - https://llvm.org/bugs/show_bug.cgi?id=28672
define i8 @big_divisor(i8 %x) {
; CHECK-LABEL: @big_divisor(
; CHECK-NEXT: [[TMP1:%.*]] = icmp ult i8 %x, -127
; CHECK-NEXT: [[TMP2:%.*]] = add i8 %x, 127
; CHECK-NEXT: [[REM:%.*]] = select i1 [[TMP1]], i8 %x, i8 [[TMP2]]
; CHECK-NEXT: ret i8 [[REM]]
;
%rem = urem i8 %x, 129
ret i8 %rem
}
define i5 @biggest_divisor(i5 %x) {
; CHECK-LABEL: @biggest_divisor(
; CHECK-NEXT: [[NOT_:%.*]] = icmp eq i5 %x, -1
; CHECK-NEXT: [[TMP1:%.*]] = zext i1 [[NOT_]] to i5
; CHECK-NEXT: [[REM:%.*]] = add i5 [[TMP1]], %x
; CHECK-NEXT: ret i5 [[REM]]
;
%rem = urem i5 %x, -1
ret i5 %rem
}
; TODO: Should vector subtract of constant be canonicalized to add?
define <2 x i4> @big_divisor_vec(<2 x i4> %x) {
; CHECK-LABEL: @big_divisor_vec(
; CHECK-NEXT: [[TMP1:%.*]] = icmp ult <2 x i4> %x, <i4 -3, i4 -3>
; CHECK-NEXT: [[TMP2:%.*]] = sub <2 x i4> %x, <i4 -3, i4 -3>
; CHECK-NEXT: [[REM:%.*]] = select <2 x i1> [[TMP1]], <2 x i4> %x, <2 x i4> [[TMP2]]
; CHECK-NEXT: ret <2 x i4> [[REM]]
;
%rem = urem <2 x i4> %x, <i4 13, i4 13>
ret <2 x i4> %rem
}