; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt < %s -passes=instcombine -S | FileCheck %s
; Fold
; x s/EXACT (1 << y)
; to
; x a>>EXACT y
; iff 1<<y is non-negative
define i8 @t0(i8 %x) {
; CHECK-LABEL: @t0(
; CHECK-NEXT: [[DIV:%.*]] = ashr exact i8 [[X:%.*]], 5
; CHECK-NEXT: ret i8 [[DIV]]
;
%div = sdiv exact i8 %x, 32
ret i8 %div
}
define i8 @n1(i8 %x) {
; CHECK-LABEL: @n1(
; CHECK-NEXT: [[DIV:%.*]] = sdiv i8 [[X:%.*]], 32
; CHECK-NEXT: ret i8 [[DIV]]
;
%div = sdiv i8 %x, 32 ; not exact
ret i8 %div
}
define i8 @n2(i8 %x) {
; CHECK-LABEL: @n2(
; CHECK-NEXT: [[TMP1:%.*]] = icmp eq i8 [[X:%.*]], -128
; CHECK-NEXT: [[DIV:%.*]] = zext i1 [[TMP1]] to i8
; CHECK-NEXT: ret i8 [[DIV]]
;
%div = sdiv i8 %x, 128 ; negative divisor
ret i8 %div
}
define <2 x i8> @t3_vec_splat(<2 x i8> %x) {
; CHECK-LABEL: @t3_vec_splat(
; CHECK-NEXT: [[DIV:%.*]] = ashr exact <2 x i8> [[X:%.*]], <i8 5, i8 5>
; CHECK-NEXT: ret <2 x i8> [[DIV]]
;
%div = sdiv exact <2 x i8> %x, <i8 32, i8 32>
ret <2 x i8> %div
}
define <2 x i8> @t4_vec(<2 x i8> %x) {
; CHECK-LABEL: @t4_vec(
; CHECK-NEXT: [[DIV:%.*]] = ashr exact <2 x i8> [[X:%.*]], <i8 5, i8 4>
; CHECK-NEXT: ret <2 x i8> [[DIV]]
;
%div = sdiv exact <2 x i8> %x, <i8 32, i8 16>
ret <2 x i8> %div
}
define <2 x i8> @n5_vec_undef(<2 x i8> %x) {
; CHECK-LABEL: @n5_vec_undef(
; CHECK-NEXT: ret <2 x i8> poison
;
%div = sdiv exact <2 x i8> %x, <i8 32, i8 undef>
ret <2 x i8> %div
}
define <2 x i8> @n6_vec_negative(<2 x i8> %x) {
; CHECK-LABEL: @n6_vec_negative(
; CHECK-NEXT: [[DIV:%.*]] = sdiv exact <2 x i8> [[X:%.*]], <i8 32, i8 -128>
; CHECK-NEXT: ret <2 x i8> [[DIV]]
;
%div = sdiv exact <2 x i8> %x, <i8 32, i8 128> ; non-non-negative divisor
ret <2 x i8> %div
}
; sdiv exact X, (1<<ShAmt) --> ashr exact X, ShAmt (if shl is non-negative)
define i8 @shl1_nsw(i8 %x, i8 %y) {
; CHECK-LABEL: @shl1_nsw(
; CHECK-NEXT: [[DIV:%.*]] = ashr exact i8 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: ret i8 [[DIV]]
;
%shl = shl nsw i8 1, %y
%div = sdiv exact i8 %x, %shl
ret i8 %div
}
; negative test - must have nsw
define i8 @shl1_nuw(i8 %x, i8 %y) {
; CHECK-LABEL: @shl1_nuw(
; CHECK-NEXT: [[SHL:%.*]] = shl nuw i8 1, [[Y:%.*]]
; CHECK-NEXT: [[DIV:%.*]] = sdiv exact i8 [[X:%.*]], [[SHL]]
; CHECK-NEXT: ret i8 [[DIV]]
;
%shl = shl nuw i8 1, %y
%div = sdiv exact i8 %x, %shl
ret i8 %div
}
; negative test - must have exact
define i8 @shl1_nsw_not_exact(i8 %x, i8 %y) {
; CHECK-LABEL: @shl1_nsw_not_exact(
; CHECK-NEXT: [[SHL:%.*]] = shl nuw nsw i8 1, [[Y:%.*]]
; CHECK-NEXT: [[DIV:%.*]] = sdiv i8 [[X:%.*]], [[SHL]]
; CHECK-NEXT: ret i8 [[DIV]]
;
%shl = shl nsw i8 1, %y
%div = sdiv i8 %x, %shl
ret i8 %div
}
define i8 @prove_exact_with_high_mask(i8 %x, i8 %y) {
; CHECK-LABEL: @prove_exact_with_high_mask(
; CHECK-NEXT: [[A:%.*]] = ashr i8 [[X:%.*]], 2
; CHECK-NEXT: [[D:%.*]] = and i8 [[A]], -2
; CHECK-NEXT: ret i8 [[D]]
;
%a = and i8 %x, -8
%d = sdiv i8 %a, 4
ret i8 %d
}
define i8 @prove_exact_with_high_mask_limit(i8 %x, i8 %y) {
; CHECK-LABEL: @prove_exact_with_high_mask_limit(
; CHECK-NEXT: [[A:%.*]] = ashr i8 [[X:%.*]], 3
; CHECK-NEXT: ret i8 [[A]]
;
%a = and i8 %x, -8
%d = sdiv i8 %a, 8
ret i8 %d
}
; negative test - not enough low zeros in dividend
define i8 @not_prove_exact_with_high_mask(i8 %x, i8 %y) {
; CHECK-LABEL: @not_prove_exact_with_high_mask(
; CHECK-NEXT: [[A:%.*]] = and i8 [[X:%.*]], -8
; CHECK-NEXT: [[D:%.*]] = sdiv i8 [[A]], 16
; CHECK-NEXT: ret i8 [[D]]
;
%a = and i8 %x, -8
%d = sdiv i8 %a, 16
ret i8 %d
}
define <2 x i8> @prove_exact_with_high_mask_splat_vec(<2 x i8> %x, <2 x i8> %y) {
; CHECK-LABEL: @prove_exact_with_high_mask_splat_vec(
; CHECK-NEXT: [[A:%.*]] = shl <2 x i8> [[X:%.*]], <i8 3, i8 3>
; CHECK-NEXT: [[D:%.*]] = ashr exact <2 x i8> [[A]], <i8 3, i8 3>
; CHECK-NEXT: ret <2 x i8> [[D]]
;
%a = shl <2 x i8> %x, <i8 3, i8 3>
%d = sdiv <2 x i8> %a, <i8 8, i8 8>
ret <2 x i8> %d
}
; TODO: Needs knownbits to handle arbitrary vector constants.
define <2 x i8> @prove_exact_with_high_mask_vec(<2 x i8> %x, <2 x i8> %y) {
; CHECK-LABEL: @prove_exact_with_high_mask_vec(
; CHECK-NEXT: [[A:%.*]] = shl <2 x i8> [[X:%.*]], <i8 3, i8 2>
; CHECK-NEXT: [[D:%.*]] = sdiv <2 x i8> [[A]], <i8 8, i8 4>
; CHECK-NEXT: ret <2 x i8> [[D]]
;
%a = shl <2 x i8> %x, <i8 3, i8 2>
%d = sdiv <2 x i8> %a, <i8 8, i8 4>
ret <2 x i8> %d
}
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