On 3 November 2016 at 17:01, Segher Boessenkool
<seg...@kernel.crashing.org> wrote:
> I managed to forget to mask the thing inserted. Tested on powerpc64-linux
> {-m32,-m64}, and Bin tested on arm. Applying to trunk.
>
>
> Segher
>
>
> 2016-11-03 Segher Boessenkool <seg...@kernel.crashing.org>
>
> PR rtl-optimization/78186
> * combine.c (change_zero_ext): Mask the RHS of a zero_extract as
> well, when converting to IOR.
>
Hi,
Since this commit I have noticed execution failures on "old" arm targets:
gcc.dg/torture/pr48124-4.c -O1 execution test
gcc.dg/torture/pr48124-4.c -O2 execution test
gcc.dg/torture/pr48124-4.c -O2 -flto -fno-use-linker-plugin
-flto-partition=none execution test
gcc.dg/torture/pr48124-4.c -O2 -flto -fuse-linker-plugin
-fno-fat-lto-objects execution test
gcc.dg/torture/pr48124-4.c -O3 -g execution test
gcc.dg/torture/pr48124-4.c -Os execution test
For instance on target arm-none-linux-gnueabi --with-cpu=cortex-a9
--with-mode=arm
and running the tests with -march=armv5t
or on arm-none-eabi with default mode/cpu and no special runtest flags
if that's easier.
Christophe
> ---
> gcc/combine.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/gcc/combine.c b/gcc/combine.c
> index 7c21fe4..7ed0a62 100644
> --- a/gcc/combine.c
> +++ b/gcc/combine.c
> @@ -11224,6 +11224,9 @@ change_zero_ext (rtx pat)
> rtx x = gen_rtx_AND (mode, reg, immed_wide_int_const (mask, mode));
> rtx y = simplify_gen_binary (ASHIFT, mode, SET_SRC (pat),
> GEN_INT (offset));
> + wide_int mask2 = wi::shifted_mask (offset, width, false, reg_width);
> + y = simplify_gen_binary (AND, mode, y,
> + immed_wide_int_const (mask2, mode));
> rtx z = simplify_gen_binary (IOR, mode, x, y);
> SUBST (SET_DEST (pat), reg);
> SUBST (SET_SRC (pat), z);
> --
> 1.9.3
>
