[LLVMbugs] [Bug 1261] instcombine miscompilation
bugzilla-daemon at cs.uiuc.edu
bugzilla-daemon at cs.uiuc.edu
Sat Apr 7 14:06:35 PDT 2007
http://llvm.org/bugs/show_bug.cgi?id=1261
rspencer at x10sys.com changed:
What |Removed |Added
----------------------------------------------------------------------------
BugsThisDependsOn|1205 |
Status|RESOLVED |REOPENED
Resolution|DUPLICATE |
------- Additional Comments From rspencer at x10sys.com 2007-04-07 16:06 -------
It seems this is a bug after all. After bug 1205 was closed (Instcombine changes
to support APInt), I reran the test case. It produced:
define i16 @test(i31 %zzz) {
entry:
%A1 = zext i31 %zzz to i32 ; <i32> [#uses=1]
%B = add i32 %A1, 16384 ; <i32> [#uses=1]
%C = lshr i32 %B, 15 ; <i32> [#uses=1]
%D = trunc i32 %C to i16 ; <i16> [#uses=1]
ret i16 %D
}
i.e. the "sext" changed to zext without any other compensating changes.
This needs to be investigated freshly to determine if the zext is okay or if
this is truly a bug.
------- You are receiving this mail because: -------
You are on the CC list for the bug, or are watching someone who is.
More information about the llvm-bugs
mailing list