llvm-project/llvm/test/Transforms/InstCombine/udiv-simplify.ll

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; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt < %s -instcombine -S | FileCheck %s
define i64 @test1(i32 %x) nounwind {
; CHECK-LABEL: @test1(
; CHECK-NEXT: ret i64 0
;
%y = lshr i32 %x, 1
%r = udiv i32 %y, -1
%z = sext i32 %r to i64
ret i64 %z
}
define i64 @test2(i32 %x) nounwind {
; CHECK-LABEL: @test2(
; CHECK-NEXT: ret i64 0
;
%y = lshr i32 %x, 31
%r = udiv i32 %y, 3
%z = sext i32 %r to i64
ret i64 %z
}
; The udiv instructions shouldn't be optimized away, and the
; sext instructions should be optimized to zext.
define i64 @test1_PR2274(i32 %x, i32 %g) nounwind {
; CHECK-LABEL: @test1_PR2274(
; CHECK-NEXT: [[Y:%.*]] = lshr i32 [[X:%.*]], 30
; CHECK-NEXT: [[R:%.*]] = udiv i32 [[Y]], [[G:%.*]]
; CHECK-NEXT: [[TMP1:%.*]] = zext i32 [[R]] to i64
; CHECK-NEXT: ret i64 [[TMP1]]
;
%y = lshr i32 %x, 30
%r = udiv i32 %y, %g
%z = sext i32 %r to i64
ret i64 %z
}
define i64 @test2_PR2274(i32 %x, i32 %v) nounwind {
; CHECK-LABEL: @test2_PR2274(
; CHECK-NEXT: [[Y:%.*]] = lshr i32 [[X:%.*]], 31
; CHECK-NEXT: [[R:%.*]] = udiv i32 [[Y]], [[V:%.*]]
; CHECK-NEXT: [[TMP1:%.*]] = zext i32 [[R]] to i64
; CHECK-NEXT: ret i64 [[TMP1]]
;
%y = lshr i32 %x, 31
%r = udiv i32 %y, %v
%z = sext i32 %r to i64
ret i64 %z
}
; The udiv should be simplified according to the rule:
; X udiv (C1 << N), where C1 is `1<<C2` --> X >> (N+C2)
@b = external global [1 x i16]
define i32 @PR30366(i1 %a) {
; CHECK-LABEL: @PR30366(
; CHECK-NEXT: [[Z:%.*]] = zext i1 [[A:%.*]] to i32
; CHECK-NEXT: [[D:%.*]] = lshr i32 [[Z]], zext (i16 ptrtoint ([1 x i16]* @b to i16) to i32)
; CHECK-NEXT: ret i32 [[D]]
;
%z = zext i1 %a to i32
%d = udiv i32 %z, zext (i16 shl (i16 1, i16 ptrtoint ([1 x i16]* @b to i16)) to i32)
ret i32 %d
}