1376301c87
InstCombine converts range tests of the form (X > C1 && X < C2) or (X < C1 || X > C2) into checks of the form (X + C3 < C4) or (X + C3 > C4). It is possible to express all range tests in either of these forms (with different choices of constants), but currently neither of them is considered canonical. We may have equivalent range tests using either ult or ugt. This proposes to canonicalize all range tests to use ult. An alternative would be to canonicalize to either ult or ugt depending on the specific constants involved -- e.g. in practice we currently generate ult for && style ranges and ugt for || style ranges when going through the insertRangeTest() helper. In fact, the "clamp like" fold was relying on this, which is why I had to tweak it to not assume whether inversion is needed based on just the predicate. Proof: https://alive2.llvm.org/ce/z/_SP_rQ Differential Revision: https://reviews.llvm.org/D113366
101 lines
3.1 KiB
LLVM
101 lines
3.1 KiB
LLVM
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
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; RUN: opt < %s -instcombine -S | FileCheck %s
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declare { i64, i1 } @llvm.smul.with.overflow.i64(i64, i64)
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declare { i8, i1 } @llvm.smul.with.overflow.i8(i8, i8)
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define i1 @test_generic(i64 %a, i64 %b) {
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; CHECK-LABEL: @test_generic(
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; CHECK-NEXT: [[RES:%.*]] = tail call { i64, i1 } @llvm.smul.with.overflow.i64(i64 [[A:%.*]], i64 [[B:%.*]])
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; CHECK-NEXT: [[OVERFLOW:%.*]] = extractvalue { i64, i1 } [[RES]], 1
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; CHECK-NEXT: ret i1 [[OVERFLOW]]
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;
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%res = tail call { i64, i1 } @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
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%overflow = extractvalue { i64, i1 } %res, 1
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ret i1 %overflow
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}
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define i1 @test_constant0(i8 %a) {
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; CHECK-LABEL: @test_constant0(
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; CHECK-NEXT: ret i1 false
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;
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%res = tail call { i8, i1 } @llvm.smul.with.overflow.i8(i8 %a, i8 0)
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%overflow = extractvalue { i8, i1 } %res, 1
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ret i1 %overflow
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}
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define i1 @test_constant1(i8 %a) {
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; CHECK-LABEL: @test_constant1(
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; CHECK-NEXT: ret i1 false
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;
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%res = tail call { i8, i1 } @llvm.smul.with.overflow.i8(i8 %a, i8 1)
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%overflow = extractvalue { i8, i1 } %res, 1
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ret i1 %overflow
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}
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define i1 @test_constant2(i8 %a) {
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; CHECK-LABEL: @test_constant2(
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; CHECK-NEXT: [[TMP1:%.*]] = add i8 [[A:%.*]], 64
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; CHECK-NEXT: [[OVERFLOW:%.*]] = icmp slt i8 [[TMP1]], 0
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; CHECK-NEXT: ret i1 [[OVERFLOW]]
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;
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%res = tail call { i8, i1 } @llvm.smul.with.overflow.i8(i8 %a, i8 2)
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%overflow = extractvalue { i8, i1 } %res, 1
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ret i1 %overflow
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}
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define i1 @test_constant3(i8 %a) {
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; CHECK-LABEL: @test_constant3(
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; CHECK-NEXT: [[TMP1:%.*]] = add i8 [[A:%.*]], -43
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; CHECK-NEXT: [[OVERFLOW:%.*]] = icmp ult i8 [[TMP1]], -85
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; CHECK-NEXT: ret i1 [[OVERFLOW]]
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;
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%res = tail call { i8, i1 } @llvm.smul.with.overflow.i8(i8 %a, i8 3)
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%overflow = extractvalue { i8, i1 } %res, 1
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ret i1 %overflow
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}
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define i1 @test_constant4(i8 %a) {
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; CHECK-LABEL: @test_constant4(
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; CHECK-NEXT: [[TMP1:%.*]] = add i8 [[A:%.*]], -32
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; CHECK-NEXT: [[OVERFLOW:%.*]] = icmp ult i8 [[TMP1]], -64
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; CHECK-NEXT: ret i1 [[OVERFLOW]]
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;
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%res = tail call { i8, i1 } @llvm.smul.with.overflow.i8(i8 %a, i8 4)
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%overflow = extractvalue { i8, i1 } %res, 1
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ret i1 %overflow
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}
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define i1 @test_constant127(i8 %a) {
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; CHECK-LABEL: @test_constant127(
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; CHECK-NEXT: [[TMP1:%.*]] = add i8 [[A:%.*]], -2
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; CHECK-NEXT: [[OVERFLOW:%.*]] = icmp ult i8 [[TMP1]], -3
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; CHECK-NEXT: ret i1 [[OVERFLOW]]
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;
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%res = tail call { i8, i1 } @llvm.smul.with.overflow.i8(i8 %a, i8 127)
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%overflow = extractvalue { i8, i1 } %res, 1
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ret i1 %overflow
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}
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define i1 @test_constant128(i8 %a) {
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; CHECK-LABEL: @test_constant128(
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; CHECK-NEXT: [[OVERFLOW:%.*]] = icmp ugt i8 [[A:%.*]], 1
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; CHECK-NEXT: ret i1 [[OVERFLOW]]
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;
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%res = tail call { i8, i1 } @llvm.smul.with.overflow.i8(i8 %a, i8 128)
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%overflow = extractvalue { i8, i1 } %res, 1
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ret i1 %overflow
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}
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define i1 @test_constant255(i8 %a) {
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; CHECK-LABEL: @test_constant255(
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; CHECK-NEXT: [[OVERFLOW:%.*]] = icmp eq i8 [[A:%.*]], -128
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; CHECK-NEXT: ret i1 [[OVERFLOW]]
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;
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%res = tail call { i8, i1 } @llvm.smul.with.overflow.i8(i8 %a, i8 255)
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%overflow = extractvalue { i8, i1 } %res, 1
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ret i1 %overflow
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}
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