1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
2; RUN: opt < %s -simplifycfg -S | FileCheck %s --check-prefixes=ALL,DEFAULT,FALLBACK0
3; RUN: opt < %s -simplifycfg -phi-node-folding-threshold=2 -S | FileCheck %s --check-prefixes=ALL,DEFAULT,FALLBACK1
4; RUN: opt < %s -simplifycfg -phi-node-folding-threshold=3 -S | FileCheck %s --check-prefixes=ALL,COSTLY
5
6; This is checking that the multiplication does overflow, with a leftover
7; guard against division-by-zero that was needed before InstCombine
8; produced llvm.umul.with.overflow.
9
10define i1 @will_overflow(i64 %size, i64 %nmemb) {
11; ALL-LABEL: @will_overflow(
12; ALL-NEXT:  entry:
13; ALL-NEXT:    [[CMP:%.*]] = icmp eq i64 [[SIZE:%.*]], 0
14; ALL-NEXT:    br i1 [[CMP]], label [[LAND_END:%.*]], label [[LAND_RHS:%.*]]
15; ALL:       land.rhs:
16; ALL-NEXT:    [[UMUL:%.*]] = tail call { i64, i1 } @llvm.umul.with.overflow.i64(i64 [[SIZE]], i64 [[NMEMB:%.*]])
17; ALL-NEXT:    [[UMUL_OV:%.*]] = extractvalue { i64, i1 } [[UMUL]], 1
18; ALL-NEXT:    [[UMUL_NOT_OV:%.*]] = xor i1 [[UMUL_OV]], true
19; ALL-NEXT:    br label [[LAND_END]]
20; ALL:       land.end:
21; ALL-NEXT:    [[TMP0:%.*]] = phi i1 [ true, [[ENTRY:%.*]] ], [ [[UMUL_NOT_OV]], [[LAND_RHS]] ]
22; ALL-NEXT:    ret i1 [[TMP0]]
23;
24entry:
25  %cmp = icmp eq i64 %size, 0
26  br i1 %cmp, label %land.end, label %land.rhs
27
28land.rhs:                                         ; preds = %entry
29  %umul = tail call { i64, i1 } @llvm.umul.with.overflow.i64(i64 %size, i64 %nmemb)
30  %umul.ov = extractvalue { i64, i1 } %umul, 1
31  %umul.not.ov = xor i1 %umul.ov, true
32  br label %land.end
33
34land.end:                                         ; preds = %land.rhs, %entry
35  %0 = phi i1 [ true, %entry ], [ %umul.not.ov, %land.rhs ]
36  ret i1 %0
37}
38
39; Function Attrs: nounwind readnone speculatable
40declare { i64, i1 } @llvm.umul.with.overflow.i64(i64, i64) #0
41