; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt < %s -simplifycfg -S | FileCheck %s

; This is checking that the multiplication does overflow, with a leftover
; guard against division-by-zero that was needed before InstCombine
; produced llvm.umul.with.overflow.

define i1 @will_overflow(i64 %size, i64 %nmemb) {
; CHECK-LABEL: @will_overflow(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i64 [[SIZE:%.*]], 0
; CHECK-NEXT:    br i1 [[CMP]], label [[LAND_END:%.*]], label [[LAND_RHS:%.*]]
; CHECK:       land.rhs:
; CHECK-NEXT:    [[UMUL:%.*]] = tail call { i64, i1 } @llvm.umul.with.overflow.i64(i64 [[SIZE]], i64 [[NMEMB:%.*]])
; CHECK-NEXT:    [[UMUL_OV:%.*]] = extractvalue { i64, i1 } [[UMUL]], 1
; CHECK-NEXT:    [[UMUL_NOT_OV:%.*]] = xor i1 [[UMUL_OV]], true
; CHECK-NEXT:    br label [[LAND_END]]
; CHECK:       land.end:
; CHECK-NEXT:    [[TMP0:%.*]] = phi i1 [ true, [[ENTRY:%.*]] ], [ [[UMUL_NOT_OV]], [[LAND_RHS]] ]
; CHECK-NEXT:    ret i1 [[TMP0]]
;
entry:
  %cmp = icmp eq i64 %size, 0
  br i1 %cmp, label %land.end, label %land.rhs

land.rhs:                                         ; preds = %entry
  %umul = tail call { i64, i1 } @llvm.umul.with.overflow.i64(i64 %size, i64 %nmemb)
  %umul.ov = extractvalue { i64, i1 } %umul, 1
  %umul.not.ov = xor i1 %umul.ov, true
  br label %land.end

land.end:                                         ; preds = %land.rhs, %entry
  %0 = phi i1 [ true, %entry ], [ %umul.not.ov, %land.rhs ]
  ret i1 %0
}

; Function Attrs: nounwind readnone speculatable
declare { i64, i1 } @llvm.umul.with.overflow.i64(i64, i64) #0

Test that we fail to flatten CFG after forming @llvm.umul.with.overflow
[SimplifyCFG][NFC] Test that we fail to flatten CFG after forming @llvm.umul.with.overflow

Even if we formed @llvm.umul.with.overflow, we are still stuck
with that guard against div-by-zero, which is no longer needed,
because we didn't flatten the CFG.

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@366749 91177308-0d34-0410-b5e6-96231b3b80d8
