[LLVMbugs] [Bug 21623] New: Instcombine folds constant @llvm.fma.f80 to wrong value

[bugzilla-daemon at llvm.org]

http://llvm.org/bugs/show_bug.cgi?id=21623

            Bug ID: 21623
           Summary: Instcombine folds constant @llvm.fma.f80 to wrong
                    value
           Product: libraries
           Version: trunk
          Hardware: PC
                OS: Linux
            Status: NEW
          Severity: normal
          Priority: P
         Component: Transformation Utilities
          Assignee: unassignedbugs at nondot.org
          Reporter: mail+llvm at tzik.jp
                CC: llvmbugs at cs.uiuc.edu
    Classification: Unclassified

InstCombine folds constant @llvm.fma.f80 to wrong value.
This can reproduce as follows, where llvm.fma.f80 is folded to
0xK40008000000000000000, which is 2.0L.

$ cat foo.ll
declare x86_fp80 @llvm.fma.f80(x86_fp80, x86_fp80, x86_fp80)

define x86_fp80 @test() {
  %1 = call x86_fp80 @llvm.fma.f80(
      x86_fp80 0xK40008000000000000000, ; 2.0L
      x86_fp80 0xK4000C000000000000000, ; 3.0L
      x86_fp80 0xK40018000000000000000) ; 4.0L

  ret x86_fp80 %1 ; should be 10.0L
}

$ opt -instcombine -S -o - foo.ll
; ModuleID = 'hoge.ll'

; Function Attrs: nounwind readnone
declare x86_fp80 @llvm.fma.f80(x86_fp80, x86_fp80, x86_fp80) #0

define x86_fp80 @test() {
  ret x86_fp80 0xK40008000000000000000
}

attributes #0 = { nounwind readnone }

-- 
You are receiving this mail because:
You are on the CC list for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-bugs/attachments/20141121/1d78fe0a/attachment.html>