This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Re: [PATCH][PR target/15184] Fix for direct byte access on x86
- From: Segher Boessenkool <segher at kernel dot crashing dot org>
- To: Jeff Law <law at redhat dot com>
- Cc: "gcc-patches at gcc dot gnu dot org >> gcc-patches" <gcc-patches at gcc dot gnu dot org>
- Date: Thu, 29 Jan 2015 14:13:31 -0600
- Subject: Re: [PATCH][PR target/15184] Fix for direct byte access on x86
- Authentication-results: sourceware.org; auth=none
- References: <54CA4407 dot 5050905 at redhat dot com>
On Thu, Jan 29, 2015 at 07:30:31AM -0700, Jeff Law wrote:
> @@ -2643,6 +2644,34 @@ try_combine (rtx_insn *i3, rtx_insn *i2, rtx_insn *i1, rtx_insn *i0,
> || GET_CODE (src) == LSHIFTRT)
> nshift++;
> }
> +
> + /* If I0 loads a memory and I3 sets the same memory, then I2 and I3
> + are likely manipulating its value. Ideally we'll be able to combine
> + all four insns into a bitfield insertion of some kind.
"I1 and I2"?
Very simple patch, nice :-)
Segher