llvm/test/Transforms/InstCombine/div.ll
Sanjay Patel bfcd22b81a [InstCombine] allow icmp (div X, Y), C folds for splat constant vectors
Converting all of the overflow ops to APInt looked risky, so I've left that as a TODO.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@280299 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-31 21:57:21 +00:00

530 lines
13 KiB
LLVM

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; This test makes sure that div instructions are properly eliminated.
; RUN: opt < %s -instcombine -S | FileCheck %s
define i32 @test1(i32 %A) {
; CHECK-LABEL: @test1(
; CHECK-NEXT: ret i32 %A
;
%B = sdiv i32 %A, 1 ; <i32> [#uses=1]
ret i32 %B
}
define i32 @test2(i32 %A) {
; => Shift
; CHECK-LABEL: @test2(
; CHECK-NEXT: [[B:%.*]] = lshr i32 %A, 3
; CHECK-NEXT: ret i32 [[B]]
;
%B = udiv i32 %A, 8 ; <i32> [#uses=1]
ret i32 %B
}
define i32 @test3(i32 %A) {
; => 0, don't need to keep traps
; CHECK-LABEL: @test3(
; CHECK-NEXT: ret i32 0
;
%B = sdiv i32 0, %A ; <i32> [#uses=1]
ret i32 %B
}
define i32 @test4(i32 %A) {
; 0-A
; CHECK-LABEL: @test4(
; CHECK-NEXT: [[B:%.*]] = sub i32 0, %A
; CHECK-NEXT: ret i32 [[B]]
;
%B = sdiv i32 %A, -1 ; <i32> [#uses=1]
ret i32 %B
}
define i32 @test5(i32 %A) {
; CHECK-LABEL: @test5(
; CHECK-NEXT: ret i32 0
;
%B = udiv i32 %A, -16 ; <i32> [#uses=1]
%C = udiv i32 %B, -4 ; <i32> [#uses=1]
ret i32 %C
}
define i1 @test6(i32 %A) {
; CHECK-LABEL: @test6(
; CHECK-NEXT: [[TMP1:%.*]] = icmp ult i32 %A, 123
; CHECK-NEXT: ret i1 [[TMP1]]
;
%B = udiv i32 %A, 123 ; <i32> [#uses=1]
; A < 123
%C = icmp eq i32 %B, 0 ; <i1> [#uses=1]
ret i1 %C
}
define i1 @test7(i32 %A) {
; CHECK-LABEL: @test7(
; CHECK-NEXT: [[A_OFF:%.*]] = add i32 %A, -20
; CHECK-NEXT: [[TMP1:%.*]] = icmp ult i32 [[A_OFF]], 10
; CHECK-NEXT: ret i1 [[TMP1]]
;
%B = udiv i32 %A, 10 ; <i32> [#uses=1]
; A >= 20 && A < 30
%C = icmp eq i32 %B, 2 ; <i1> [#uses=1]
ret i1 %C
}
define <2 x i1> @test7vec(<2 x i32> %A) {
; CHECK-LABEL: @test7vec(
; CHECK-NEXT: [[A_OFF:%.*]] = add <2 x i32> %A, <i32 -20, i32 -20>
; CHECK-NEXT: [[TMP1:%.*]] = icmp ult <2 x i32> [[A_OFF]], <i32 10, i32 10>
; CHECK-NEXT: ret <2 x i1> [[TMP1]]
;
%B = udiv <2 x i32> %A, <i32 10, i32 10>
%C = icmp eq <2 x i32> %B, <i32 2, i32 2>
ret <2 x i1> %C
}
define i1 @test8(i8 %A) {
; CHECK-LABEL: @test8(
; CHECK-NEXT: [[C:%.*]] = icmp ugt i8 %A, -11
; CHECK-NEXT: ret i1 [[C]]
;
%B = udiv i8 %A, 123 ; <i8> [#uses=1]
; A >= 246
%C = icmp eq i8 %B, 2 ; <i1> [#uses=1]
ret i1 %C
}
define <2 x i1> @test8vec(<2 x i8> %A) {
; CHECK-LABEL: @test8vec(
; CHECK-NEXT: [[C:%.*]] = icmp ugt <2 x i8> %A, <i8 -11, i8 -11>
; CHECK-NEXT: ret <2 x i1> [[C]]
;
%B = udiv <2 x i8> %A, <i8 123, i8 123>
%C = icmp eq <2 x i8> %B, <i8 2, i8 2>
ret <2 x i1> %C
}
define i1 @test9(i8 %A) {
; CHECK-LABEL: @test9(
; CHECK-NEXT: [[C:%.*]] = icmp ult i8 %A, -10
; CHECK-NEXT: ret i1 [[C]]
;
%B = udiv i8 %A, 123 ; <i8> [#uses=1]
; A < 246
%C = icmp ne i8 %B, 2 ; <i1> [#uses=1]
ret i1 %C
}
define <2 x i1> @test9vec(<2 x i8> %A) {
; CHECK-LABEL: @test9vec(
; CHECK-NEXT: [[C:%.*]] = icmp ult <2 x i8> %A, <i8 -10, i8 -10>
; CHECK-NEXT: ret <2 x i1> [[C]]
;
%B = udiv <2 x i8> %A, <i8 123, i8 123>
%C = icmp ne <2 x i8> %B, <i8 2, i8 2>
ret <2 x i1> %C
}
define i32 @test10(i32 %X, i1 %C) {
; CHECK-LABEL: @test10(
; CHECK-NEXT: [[R_V:%.*]] = select i1 %C, i32 6, i32 3
; CHECK-NEXT: [[R:%.*]] = lshr i32 %X, [[R:%.*]].v
; CHECK-NEXT: ret i32 [[R]]
;
%V = select i1 %C, i32 64, i32 8 ; <i32> [#uses=1]
%R = udiv i32 %X, %V ; <i32> [#uses=1]
ret i32 %R
}
define i32 @test11(i32 %X, i1 %C) {
; CHECK-LABEL: @test11(
; CHECK-NEXT: [[B_V:%.*]] = select i1 %C, i32 10, i32 5
; CHECK-NEXT: [[B:%.*]] = lshr i32 %X, [[B:%.*]].v
; CHECK-NEXT: ret i32 [[B]]
;
%A = select i1 %C, i32 1024, i32 32 ; <i32> [#uses=1]
%B = udiv i32 %X, %A ; <i32> [#uses=1]
ret i32 %B
}
; PR2328
define i32 @test12(i32 %x) nounwind {
; CHECK-LABEL: @test12(
; CHECK-NEXT: ret i32 1
;
%tmp3 = udiv i32 %x, %x ; 1
ret i32 %tmp3
}
define i32 @test13(i32 %x) nounwind {
; CHECK-LABEL: @test13(
; CHECK-NEXT: ret i32 1
;
%tmp3 = sdiv i32 %x, %x ; 1
ret i32 %tmp3
}
define i32 @test14(i8 %x) nounwind {
; CHECK-LABEL: @test14(
; CHECK-NEXT: ret i32 0
;
%zext = zext i8 %x to i32
%div = udiv i32 %zext, 257 ; 0
ret i32 %div
}
; PR9814
define i32 @test15(i32 %a, i32 %b) nounwind {
; CHECK-LABEL: @test15(
; CHECK-NEXT: [[TMP1:%.*]] = add i32 %b, -2
; CHECK-NEXT: [[DIV2:%.*]] = lshr i32 %a, [[TMP1]]
; CHECK-NEXT: ret i32 [[DIV2]]
;
%shl = shl i32 1, %b
%div = lshr i32 %shl, 2
%div2 = udiv i32 %a, %div
ret i32 %div2
}
define <2 x i64> @test16(<2 x i64> %x) nounwind {
; CHECK-LABEL: @test16(
; CHECK-NEXT: [[DIV:%.*]] = udiv <2 x i64> %x, <i64 192, i64 192>
; CHECK-NEXT: ret <2 x i64> [[DIV]]
;
%shr = lshr <2 x i64> %x, <i64 5, i64 5>
%div = udiv <2 x i64> %shr, <i64 6, i64 6>
ret <2 x i64> %div
}
define <2 x i64> @test17(<2 x i64> %x) nounwind {
; CHECK-LABEL: @test17(
; CHECK-NEXT: [[DIV:%.*]] = sdiv <2 x i64> %x, <i64 -3, i64 -4>
; CHECK-NEXT: ret <2 x i64> [[DIV]]
;
%neg = sub nsw <2 x i64> zeroinitializer, %x
%div = sdiv <2 x i64> %neg, <i64 3, i64 4>
ret <2 x i64> %div
}
define <2 x i64> @test18(<2 x i64> %x) nounwind {
; CHECK-LABEL: @test18(
; CHECK-NEXT: [[DIV:%.*]] = sub <2 x i64> zeroinitializer, %x
; CHECK-NEXT: ret <2 x i64> [[DIV]]
;
%div = sdiv <2 x i64> %x, <i64 -1, i64 -1>
ret <2 x i64> %div
}
define i32 @test19(i32 %x) {
; CHECK-LABEL: @test19(
; CHECK-NEXT: [[TMP1:%.*]] = icmp eq i32 %x, 1
; CHECK-NEXT: [[A:%.*]] = zext i1 [[TMP1]] to i32
; CHECK-NEXT: ret i32 [[A]]
;
%A = udiv i32 1, %x
ret i32 %A
}
define i32 @test20(i32 %x) {
; CHECK-LABEL: @test20(
; CHECK-NEXT: [[TMP1:%.*]] = add i32 %x, 1
; CHECK-NEXT: [[TMP2:%.*]] = icmp ult i32 [[TMP1]], 3
; CHECK-NEXT: [[A:%.*]] = select i1 [[TMP2]], i32 %x, i32 0
; CHECK-NEXT: ret i32 [[A]]
;
%A = sdiv i32 1, %x
ret i32 %A
}
define i32 @test21(i32 %a) {
; CHECK-LABEL: @test21(
; CHECK-NEXT: [[DIV:%.*]] = sdiv i32 %a, 3
; CHECK-NEXT: ret i32 [[DIV]]
;
%shl = shl nsw i32 %a, 2
%div = sdiv i32 %shl, 12
ret i32 %div
}
define i32 @test22(i32 %a) {
; CHECK-LABEL: @test22(
; CHECK-NEXT: [[DIV:%.*]] = sdiv i32 %a, 4
; CHECK-NEXT: ret i32 [[DIV]]
;
%mul = mul nsw i32 %a, 3
%div = sdiv i32 %mul, 12
ret i32 %div
}
define i32 @test23(i32 %a) {
; CHECK-LABEL: @test23(
; CHECK-NEXT: [[DIV:%.*]] = udiv i32 %a, 3
; CHECK-NEXT: ret i32 [[DIV]]
;
%shl = shl nuw i32 %a, 2
%div = udiv i32 %shl, 12
ret i32 %div
}
define i32 @test24(i32 %a) {
; CHECK-LABEL: @test24(
; CHECK-NEXT: [[DIV:%.*]] = lshr i32 %a, 2
; CHECK-NEXT: ret i32 [[DIV]]
;
%mul = mul nuw i32 %a, 3
%div = udiv i32 %mul, 12
ret i32 %div
}
define i32 @test25(i32 %a) {
; CHECK-LABEL: @test25(
; CHECK-NEXT: [[DIV:%.*]] = shl nsw i32 %a, 1
; CHECK-NEXT: ret i32 [[DIV]]
;
%shl = shl nsw i32 %a, 2
%div = sdiv i32 %shl, 2
ret i32 %div
}
define i32 @test26(i32 %a) {
; CHECK-LABEL: @test26(
; CHECK-NEXT: [[DIV:%.*]] = shl nsw i32 %a, 2
; CHECK-NEXT: ret i32 [[DIV]]
;
%mul = mul nsw i32 %a, 12
%div = sdiv i32 %mul, 3
ret i32 %div
}
define i32 @test27(i32 %a) {
; CHECK-LABEL: @test27(
; CHECK-NEXT: [[DIV:%.*]] = shl nuw i32 %a, 1
; CHECK-NEXT: ret i32 [[DIV]]
;
%shl = shl nuw i32 %a, 2
%div = udiv i32 %shl, 2
ret i32 %div
}
define i32 @test28(i32 %a) {
; CHECK-LABEL: @test28(
; CHECK-NEXT: [[DIV:%.*]] = mul nuw i32 %a, 12
; CHECK-NEXT: ret i32 [[DIV]]
;
%mul = mul nuw i32 %a, 36
%div = udiv i32 %mul, 3
ret i32 %div
}
define i32 @test29(i32 %a) {
; CHECK-LABEL: @test29(
; CHECK-NEXT: [[MUL_LOBIT:%.*]] = and i32 %a, 1
; CHECK-NEXT: ret i32 [[MUL_LOBIT]]
;
%mul = shl nsw i32 %a, 31
%div = sdiv i32 %mul, -2147483648
ret i32 %div
}
define i32 @test30(i32 %a) {
; CHECK-LABEL: @test30(
; CHECK-NEXT: ret i32 %a
;
%mul = shl nuw i32 %a, 31
%div = udiv i32 %mul, -2147483648
ret i32 %div
}
define <2 x i32> @test31(<2 x i32> %x) {
; CHECK-LABEL: @test31(
; CHECK-NEXT: ret <2 x i32> zeroinitializer
;
%shr = lshr <2 x i32> %x, <i32 31, i32 31>
%div = udiv <2 x i32> %shr, <i32 2147483647, i32 2147483647>
ret <2 x i32> %div
}
define i32 @test32(i32 %a, i32 %b) {
; CHECK-LABEL: @test32(
; CHECK-NEXT: [[SHL:%.*]] = shl i32 2, %b
; CHECK-NEXT: [[DIV:%.*]] = lshr i32 [[SHL]], 2
; CHECK-NEXT: [[DIV2:%.*]] = udiv i32 %a, [[DIV]]
; CHECK-NEXT: ret i32 [[DIV2]]
;
%shl = shl i32 2, %b
%div = lshr i32 %shl, 2
%div2 = udiv i32 %a, %div
ret i32 %div2
}
define <2 x i64> @test33(<2 x i64> %x) nounwind {
; CHECK-LABEL: @test33(
; CHECK-NEXT: [[DIV:%.*]] = udiv exact <2 x i64> %x, <i64 192, i64 192>
; CHECK-NEXT: ret <2 x i64> [[DIV]]
;
%shr = lshr exact <2 x i64> %x, <i64 5, i64 5>
%div = udiv exact <2 x i64> %shr, <i64 6, i64 6>
ret <2 x i64> %div
}
define <2 x i64> @test34(<2 x i64> %x) nounwind {
; CHECK-LABEL: @test34(
; CHECK-NEXT: [[DIV:%.*]] = sdiv exact <2 x i64> %x, <i64 -3, i64 -4>
; CHECK-NEXT: ret <2 x i64> [[DIV]]
;
%neg = sub nsw <2 x i64> zeroinitializer, %x
%div = sdiv exact <2 x i64> %neg, <i64 3, i64 4>
ret <2 x i64> %div
}
define i32 @test35(i32 %A) {
; CHECK-LABEL: @test35(
; CHECK-NEXT: [[AND:%.*]] = and i32 %A, 2147483647
; CHECK-NEXT: [[MUL:%.*]] = udiv exact i32 [[AND]], 2147483647
; CHECK-NEXT: ret i32 [[MUL]]
;
%and = and i32 %A, 2147483647
%mul = sdiv exact i32 %and, 2147483647
ret i32 %mul
}
define i32 @test36(i32 %A) {
; CHECK-LABEL: @test36(
; CHECK-NEXT: [[AND:%.*]] = and i32 %A, 2147483647
; CHECK-NEXT: [[MUL:%.*]] = lshr exact i32 [[AND]], %A
; CHECK-NEXT: ret i32 [[MUL]]
;
%and = and i32 %A, 2147483647
%shl = shl nsw i32 1, %A
%mul = sdiv exact i32 %and, %shl
ret i32 %mul
}
; FIXME: Vector should get same transform as scalar.
define <2 x i32> @test36vec(<2 x i32> %A) {
; CHECK-LABEL: @test36vec(
; CHECK-NEXT: [[AND:%.*]] = and <2 x i32> %A, <i32 2147483647, i32 2147483647>
; CHECK-NEXT: [[SHL:%.*]] = shl nuw nsw <2 x i32> <i32 1, i32 1>, %A
; CHECK-NEXT: [[MUL:%.*]] = sdiv exact <2 x i32> [[AND]], [[SHL]]
; CHECK-NEXT: ret <2 x i32> [[MUL]]
;
%and = and <2 x i32> %A, <i32 2147483647, i32 2147483647>
%shl = shl nsw <2 x i32> <i32 1, i32 1>, %A
%mul = sdiv exact <2 x i32> %and, %shl
ret <2 x i32> %mul
}
define i32 @test37(i32* %b) {
; CHECK-LABEL: @test37(
; CHECK-NEXT: entry:
; CHECK-NEXT: store i32 0, i32* %b, align 4
; CHECK-NEXT: br i1 undef, label %lor.rhs, label %lor.end
; CHECK: lor.rhs:
; CHECK-NEXT: br label %lor.end
; CHECK: lor.end:
; CHECK-NEXT: ret i32 0
;
entry:
store i32 0, i32* %b, align 4
%0 = load i32, i32* %b, align 4
br i1 undef, label %lor.rhs, label %lor.end
lor.rhs: ; preds = %entry
%mul = mul nsw i32 undef, %0
br label %lor.end
lor.end: ; preds = %lor.rhs, %entry
%t.0 = phi i32 [ %0, %entry ], [ %mul, %lor.rhs ]
%div = sdiv i32 %t.0, 2
ret i32 %div
}
; We can perform the division in the smaller type.
define i32 @shrink(i8 %x) {
; CHECK-LABEL: @shrink(
; CHECK-NEXT: [[TMP1:%.*]] = sdiv i8 %x, 127
; CHECK-NEXT: [[DIV:%.*]] = sext i8 [[TMP1]] to i32
; CHECK-NEXT: ret i32 [[DIV]]
;
%conv = sext i8 %x to i32
%div = sdiv i32 %conv, 127
ret i32 %div
}
; Division in the smaller type can lead to more optimizations.
define i32 @zap(i8 %x) {
; CHECK-LABEL: @zap(
; CHECK-NEXT: [[TMP1:%.*]] = icmp eq i8 %x, -128
; CHECK-NEXT: [[DIV:%.*]] = zext i1 [[TMP1]] to i32
; CHECK-NEXT: ret i32 [[DIV]]
;
%conv = sext i8 %x to i32
%div = sdiv i32 %conv, -128
ret i32 %div
}
; Splat constant divisors should get the same folds.
define <3 x i32> @shrink_vec(<3 x i8> %x) {
; CHECK-LABEL: @shrink_vec(
; CHECK-NEXT: [[TMP1:%.*]] = sdiv <3 x i8> %x, <i8 127, i8 127, i8 127>
; CHECK-NEXT: [[DIV:%.*]] = sext <3 x i8> [[TMP1]] to <3 x i32>
; CHECK-NEXT: ret <3 x i32> [[DIV]]
;
%conv = sext <3 x i8> %x to <3 x i32>
%div = sdiv <3 x i32> %conv, <i32 127, i32 127, i32 127>
ret <3 x i32> %div
}
define <2 x i32> @zap_vec(<2 x i8> %x) {
; CHECK-LABEL: @zap_vec(
; CHECK-NEXT: [[TMP1:%.*]] = icmp eq <2 x i8> %x, <i8 -128, i8 -128>
; CHECK-NEXT: [[DIV:%.*]] = zext <2 x i1> [[TMP1]] to <2 x i32>
; CHECK-NEXT: ret <2 x i32> [[DIV]]
;
%conv = sext <2 x i8> %x to <2 x i32>
%div = sdiv <2 x i32> %conv, <i32 -128, i32 -128>
ret <2 x i32> %div
}
; But we can't do this if the signed constant won't fit in the original type.
define i32 @shrink_no(i8 %x) {
; CHECK-LABEL: @shrink_no(
; CHECK-NEXT: [[CONV:%.*]] = sext i8 %x to i32
; CHECK-NEXT: [[DIV:%.*]] = sdiv i32 [[CONV]], 128
; CHECK-NEXT: ret i32 [[DIV]]
;
%conv = sext i8 %x to i32
%div = sdiv i32 %conv, 128
ret i32 %div
}
define i32 @shrink_no2(i8 %x) {
; CHECK-LABEL: @shrink_no2(
; CHECK-NEXT: [[CONV:%.*]] = sext i8 %x to i32
; CHECK-NEXT: [[DIV:%.*]] = sdiv i32 [[CONV]], -129
; CHECK-NEXT: ret i32 [[DIV]]
;
%conv = sext i8 %x to i32
%div = sdiv i32 %conv, -129
ret i32 %div
}
; 17 bits are needed to represent 65535 as a signed value, so this shouldn't fold.
define i32 @shrink_no3(i16 %x) {
; CHECK-LABEL: @shrink_no3(
; CHECK-NEXT: [[CONV:%.*]] = sext i16 %x to i32
; CHECK-NEXT: [[DIV:%.*]] = sdiv i32 [[CONV]], 65535
; CHECK-NEXT: ret i32 [[DIV]]
;
%conv = sext i16 %x to i32
%div = sdiv i32 %conv, 65535
ret i32 %div
}