[PATCH] D151887: InstSimplify: Start cleaning up simplifyFCmpInst

[Zequan Wu via Phabricator via llvm-commits]

zequanwu added a comment.

Attach reduced IR:

  target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
  target triple = "x86_64-unknown-linux-gnu"
  
  ; Function Attrs: null_pointer_is_valid
  define i1 @_ZNK3gfx10ColorSpace25IsTransferFunctionEqualToERK22skcms_TransferFunction(ptr %this, float %0) #0 {
  entry:
    store float 0xFFFFFFFFE0000000, ptr %this, align 4
    %call = call i1 @_ZNK3gfx10ColorSpace19GetTransferFunctionEP22skcms_TransferFunctionN4absl8optionalIfEE()
    %1 = load float, ptr %this, align 4
    %cmp = fcmp oeq float %1, %0
    br i1 %cmp, label %land.lhs.true, label %land.end
  
  land.lhs.true:                                    ; preds = %entry
    %2 = load float, ptr null, align 4294967296
    %tobool = fcmp une float %2, 0.000000e+00
    br i1 %tobool, label %land.rhs, label %land.end
  
  land.rhs:                                         ; preds = %land.lhs.true
    br label %land.end
  
  land.end:                                         ; preds = %land.rhs, %land.lhs.true, %entry
    %3 = phi i1 [ false, %land.lhs.true ], [ false, %entry ], [ true, %land.rhs ]
    ret i1 %3
  }
  
  ; Function Attrs: null_pointer_is_valid
  define i1 @_ZNK3gfx10ColorSpace19GetTransferFunctionEP22skcms_TransferFunctionN4absl8optionalIfEE() #0 {
  entry:
    %0 = load i8, ptr null, align 4294967296
    switch i8 %0, label %sw.default [
      i8 0, label %common.ret
      i8 1, label %common.ret
    ]
  
  common.ret:                                       ; preds = %sw.default, %entry, %entry
    ret i1 false
  
  sw.default:                                       ; preds = %entry
    %call6 = call i1 null(i8 0, ptr null)
    br label %common.ret
  }
  
  attributes #0 = { null_pointer_is_valid }

This command triggers the error even with the fix (0637b00041c7d6a191d51d9966c4f5f41fb97ab5 <https://reviews.llvm.org/rG0637b00041c7d6a191d51d9966c4f5f41fb97ab5>):

  opt '-passes=default<O2>' reduce.ll


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D151887/new/

https://reviews.llvm.org/D151887