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[ValueTracking] remove overzealous assert 

The test is derived from a failing fuzz test:
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=5008

Credit to @rksimon for pointing out the problem.

llvm-svn: 322016
This commit is contained in:
Sanjay Patel 2018-01-08 18:31:13 +00:00
parent e9500ba745
commit 7dfe96ad16
2 changed files with 22 additions and 1 deletions
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2
llvm/lib/Analysis/ValueTracking.cpp
View File

@ -4214,7 +4214,7 @@ static SelectPatternResult matchMinMaxOfMinMax(CmpInst::Predicate Pred,
break;
return {SPF_UNKNOWN, SPNB_NA, false};
default:
llvm_unreachable("Bad flavor while matching min/max");
return {SPF_UNKNOWN, SPNB_NA, false};
}
// a pred c ? m(a, b) : m(c, b) --> m(m(a, b), m(c, b))

21
llvm/test/Transforms/InstCombine/minmax-fold.ll
View File

@ -887,3 +887,24 @@ define i32 @common_factor_umax_extra_use_both(i32 %a, i32 %b, i32 %c) {
ret i32 %max_abc
}
; This would assert. Don't assume that earlier min/max types match a possible later min/max.
define float @not_min_of_min(i8 %i, float %x) {
; CHECK-LABEL: @not_min_of_min(
; CHECK-NEXT: [[CMP1_INV:%.*]] = fcmp fast oge float [[X:%.*]], 1.000000e+00
; CHECK-NEXT: [[MIN1:%.*]] = select i1 [[CMP1_INV]], float 1.000000e+00, float [[X]]
; CHECK-NEXT: [[CMP2_INV:%.*]] = fcmp fast oge float [[X]], 2.000000e+00
; CHECK-NEXT: [[MIN2:%.*]] = select i1 [[CMP2_INV]], float 2.000000e+00, float [[X]]
; CHECK-NEXT: [[CMP3:%.*]] = icmp ult i8 [[I:%.*]], 16
; CHECK-NEXT: [[R:%.*]] = select i1 [[CMP3]], float [[MIN1]], float [[MIN2]]
; CHECK-NEXT: ret float [[R]]
;
%cmp1 = fcmp fast ult float %x, 1.0
%min1 = select i1 %cmp1, float %x, float 1.0
%cmp2 = fcmp fast ult float %x, 2.0
%min2 = select i1 %cmp2, float %x, float 2.0
%cmp3 = icmp ult i8 %i, 16
%r = select i1 %cmp3, float %min1, float %min2
ret float %r
}