umul-sign-check.ll 7.53 KB
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt -instcombine -S %s | FileCheck %s

; Check that we simplify llvm.umul.with.overflow, if the overflow check is
; weakened by or (icmp ne %res, 0) %overflow. This is generated by code using
; __builtin_mul_overflow with negative integer constants, e.g.

;   bool test(unsigned long long v, unsigned long long *res) {
;     return __builtin_mul_overflow(v, -4775807LL, res);
;   }

declare { i64, i1 } @llvm.umul.with.overflow.i64(i64, i64) #0

define i1 @test1(i64 %a, i64 %b, i64* %ptr) {
; CHECK-LABEL: @test1(
; CHECK-NEXT:    [[MUL:%.*]] = mul i64 [[A:%.*]], [[B:%.*]]
; CHECK-NEXT:    [[TMP1:%.*]] = icmp ne i64 [[A]], 0
; CHECK-NEXT:    [[TMP2:%.*]] = icmp ne i64 [[B]], 0
; CHECK-NEXT:    [[OVERFLOW_1:%.*]] = and i1 [[TMP1]], [[TMP2]]
; CHECK-NEXT:    store i64 [[MUL]], i64* [[PTR:%.*]], align 8
; CHECK-NEXT:    ret i1 [[OVERFLOW_1]]
;

  %res = tail call { i64, i1 } @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
  %overflow = extractvalue { i64, i1 } %res, 1
  %mul = extractvalue { i64, i1 } %res, 0
  %cmp  = icmp ne i64 %mul, 0
  %overflow.1 = or i1 %overflow, %cmp
  store i64 %mul, i64* %ptr, align 8
  ret i1 %overflow.1
}

define i1 @test1_or_ops_swapped(i64 %a, i64 %b, i64* %ptr) {
; CHECK-LABEL: @test1_or_ops_swapped(
; CHECK-NEXT:    [[MUL:%.*]] = mul i64 [[A:%.*]], [[B:%.*]]
; CHECK-NEXT:    [[TMP1:%.*]] = icmp ne i64 [[A]], 0
; CHECK-NEXT:    [[TMP2:%.*]] = icmp ne i64 [[B]], 0
; CHECK-NEXT:    [[OVERFLOW_1:%.*]] = and i1 [[TMP1]], [[TMP2]]
; CHECK-NEXT:    store i64 [[MUL]], i64* [[PTR:%.*]], align 8
; CHECK-NEXT:    ret i1 [[OVERFLOW_1]]
;


  %res = tail call { i64, i1 } @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
  %overflow = extractvalue { i64, i1 } %res, 1
  %mul = extractvalue { i64, i1 } %res, 0
  %cmp  = icmp ne i64 %mul, 0
  %overflow.1 = or i1 %cmp, %overflow
  store i64 %mul, i64* %ptr, align 8
  ret i1 %overflow.1
}

define i1 @test2(i64 %a, i64 %b, i64* %ptr) {
; CHECK-LABEL: @test2(
; CHECK-NEXT:    [[MUL:%.*]] = mul i64 [[A:%.*]], [[B:%.*]]
; CHECK-NEXT:    [[TMP1:%.*]] = icmp ne i64 [[A]], 0
; CHECK-NEXT:    [[TMP2:%.*]] = icmp ne i64 [[B]], 0
; CHECK-NEXT:    [[OVERFLOW_1:%.*]] = and i1 [[TMP1]], [[TMP2]]
; CHECK-NEXT:    [[NEG:%.*]] = sub i64 0, [[MUL]]
; CHECK-NEXT:    store i64 [[NEG]], i64* [[PTR:%.*]], align 8
; CHECK-NEXT:    ret i1 [[OVERFLOW_1]]
;

  %res = tail call { i64, i1 } @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
  %overflow = extractvalue { i64, i1 } %res, 1
  %mul = extractvalue { i64, i1 } %res, 0
  %cmp = icmp ne i64 %mul, 0
  %overflow.1 = or i1 %overflow, %cmp
  %neg = sub i64 0, %mul
  store i64 %neg, i64* %ptr, align 8
  ret i1 %overflow.1
}

declare void @use(i1)

define i1 @test3_multiple_overflow_users(i64 %a, i64 %b, i64* %ptr) {
; CHECK-LABEL: @test3_multiple_overflow_users(
; CHECK-NEXT:    [[RES:%.*]] = tail call { i64, i1 } @llvm.umul.with.overflow.i64(i64 [[A:%.*]], i64 [[B:%.*]])
; CHECK-NEXT:    [[OVERFLOW:%.*]] = extractvalue { i64, i1 } [[RES]], 1
; CHECK-NEXT:    [[TMP1:%.*]] = icmp ne i64 [[A]], 0
; CHECK-NEXT:    [[TMP2:%.*]] = icmp ne i64 [[B]], 0
; CHECK-NEXT:    [[OVERFLOW_1:%.*]] = and i1 [[TMP1]], [[TMP2]]
; CHECK-NEXT:    call void @use(i1 [[OVERFLOW]])
; CHECK-NEXT:    ret i1 [[OVERFLOW_1]]
;
  %res = tail call { i64, i1 } @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
  %overflow = extractvalue { i64, i1 } %res, 1
  %mul = extractvalue { i64, i1 } %res, 0
  %cmp = icmp ne i64 %mul, 0
  %overflow.1 = or i1 %overflow, %cmp
  call void @use(i1 %overflow)
  ret i1 %overflow.1
}

; Do not simplify if %overflow and %mul have multiple uses.
define i1 @test3_multiple_overflow_and_mul_users(i64 %a, i64 %b, i64* %ptr) {
; CHECK-LABEL: @test3_multiple_overflow_and_mul_users(
; CHECK-NEXT:    [[RES:%.*]] = tail call { i64, i1 } @llvm.umul.with.overflow.i64(i64 [[A:%.*]], i64 [[B:%.*]])
; CHECK-NEXT:    [[OVERFLOW:%.*]] = extractvalue { i64, i1 } [[RES]], 1
; CHECK-NEXT:    [[MUL:%.*]] = extractvalue { i64, i1 } [[RES]], 0
; CHECK-NEXT:    [[CMP:%.*]] = icmp ne i64 [[MUL]], 0
; CHECK-NEXT:    [[OVERFLOW_1:%.*]] = or i1 [[OVERFLOW]], [[CMP]]
; CHECK-NEXT:    [[NEG:%.*]] = sub i64 0, [[MUL]]
; CHECK-NEXT:    store i64 [[NEG]], i64* [[PTR:%.*]], align 8
; CHECK-NEXT:    call void @use(i1 [[OVERFLOW]])
; CHECK-NEXT:    ret i1 [[OVERFLOW_1]]
;
  %res = tail call { i64, i1 } @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
  %overflow = extractvalue { i64, i1 } %res, 1
  %mul = extractvalue { i64, i1 } %res, 0
  %cmp = icmp ne i64 %mul, 0
  %overflow.1 = or i1 %overflow, %cmp
  %neg = sub i64 0, %mul
  store i64 %neg, i64* %ptr, align 8
  call void @use(i1 %overflow)
  ret i1 %overflow.1
}


declare void @use.2({ i64, i1 })
define i1 @test3_multiple_res_users(i64 %a, i64 %b, i64* %ptr) {
; CHECK-LABEL: @test3_multiple_res_users(
; CHECK-NEXT:    [[RES:%.*]] = tail call { i64, i1 } @llvm.umul.with.overflow.i64(i64 [[A:%.*]], i64 [[B:%.*]])
; CHECK-NEXT:    [[MUL:%.*]] = extractvalue { i64, i1 } [[RES]], 0
; CHECK-NEXT:    [[TMP1:%.*]] = icmp ne i64 [[A]], 0
; CHECK-NEXT:    [[TMP2:%.*]] = icmp ne i64 [[B]], 0
; CHECK-NEXT:    [[OVERFLOW_1:%.*]] = and i1 [[TMP1]], [[TMP2]]
; CHECK-NEXT:    [[NEG:%.*]] = sub i64 0, [[MUL]]
; CHECK-NEXT:    store i64 [[NEG]], i64* [[PTR:%.*]], align 8
; CHECK-NEXT:    call void @use.2({ i64, i1 } [[RES]])
; CHECK-NEXT:    ret i1 [[OVERFLOW_1]]
;
  %res = tail call { i64, i1 } @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
  %overflow = extractvalue { i64, i1 } %res, 1
  %mul = extractvalue { i64, i1 } %res, 0
  %cmp = icmp ne i64 %mul, 0
  %overflow.1 = or i1 %overflow, %cmp
  %neg = sub i64 0, %mul
  store i64 %neg, i64* %ptr, align 8
  call void @use.2({ i64, i1 } %res)
  ret i1 %overflow.1
}

declare void @use.3(i64)

; Simplify if %mul has multiple uses.
define i1 @test3_multiple_mul_users(i64 %a, i64 %b, i64* %ptr) {
; CHECK-LABEL: @test3_multiple_mul_users(
; CHECK-NEXT:    [[MUL:%.*]] = mul i64 [[A:%.*]], [[B:%.*]]
; CHECK-NEXT:    [[TMP1:%.*]] = icmp ne i64 [[A]], 0
; CHECK-NEXT:    [[TMP2:%.*]] = icmp ne i64 [[B]], 0
; CHECK-NEXT:    [[OVERFLOW_1:%.*]] = and i1 [[TMP1]], [[TMP2]]
; CHECK-NEXT:    [[NEG:%.*]] = sub i64 0, [[MUL]]
; CHECK-NEXT:    store i64 [[NEG]], i64* [[PTR:%.*]], align 8
; CHECK-NEXT:    call void @use.3(i64 [[MUL]])
; CHECK-NEXT:    ret i1 [[OVERFLOW_1]]
;

  %res = tail call { i64, i1 } @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
  %overflow = extractvalue { i64, i1 } %res, 1
  %mul = extractvalue { i64, i1 } %res, 0
  %cmp = icmp ne i64 %mul, 0
  %overflow.1 = or i1 %overflow, %cmp
  %neg = sub i64 0, %mul
  store i64 %neg, i64* %ptr, align 8
  call void @use.3(i64 %mul)
  ret i1 %overflow.1
}



define i1 @test4_no_icmp_ne(i64 %a, i64 %b, i64* %ptr) {
; CHECK-LABEL: @test4_no_icmp_ne(
; CHECK-NEXT:    [[RES:%.*]] = tail call { i64, i1 } @llvm.umul.with.overflow.i64(i64 [[A:%.*]], i64 [[B:%.*]])
; CHECK-NEXT:    [[OVERFLOW:%.*]] = extractvalue { i64, i1 } [[RES]], 1
; CHECK-NEXT:    [[MUL:%.*]] = extractvalue { i64, i1 } [[RES]], 0
; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i64 [[MUL]], 0
; CHECK-NEXT:    [[OVERFLOW_1:%.*]] = or i1 [[OVERFLOW]], [[CMP]]
; CHECK-NEXT:    [[NEG:%.*]] = sub i64 0, [[MUL]]
; CHECK-NEXT:    store i64 [[NEG]], i64* [[PTR:%.*]], align 8
; CHECK-NEXT:    ret i1 [[OVERFLOW_1]]
;
  %res = tail call { i64, i1 } @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
  %overflow = extractvalue { i64, i1 } %res, 1
  %mul = extractvalue { i64, i1 } %res, 0
  %cmp = icmp sgt i64 %mul, 0
  %overflow.1 = or i1 %overflow, %cmp
  %neg = sub i64 0, %mul
  store i64 %neg, i64* %ptr, align 8
  ret i1 %overflow.1
}

attributes #0 = { nounwind readnone speculatable willreturn }