[Bug target/49526] ARM missed optimization: SMMUL instruction

[siarhei.siamashka at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49526

--- Comment #1 from Siarhei Siamashka <siarhei.siamashka at gmail dot com> 
2011-06-24 22:48:46 UTC ---
And clang 2.9 has no problems optimizing this code:

$ cat test.c

int smmul(int a, int b) { return ((long long)a * b) >> 32; }

$ clang -ccc-host-triple arm-none-linux -O2 -mcpu=cortex-a8 -S test.c
$ cat test.s
        .syntax unified
        .cpu cortex-a8
        .eabi_attribute 6, 10
        .eabi_attribute 7, 65
        .eabi_attribute 8, 1
        .eabi_attribute 9, 2
        .fpu neon
        .eabi_attribute 10, 3
        .eabi_attribute 12, 1
        .eabi_attribute 20, 1
        .eabi_attribute 21, 1
        .eabi_attribute 23, 3
        .eabi_attribute 24, 1
        .eabi_attribute 25, 1
        .file   "test.c"
        .text
        .globl  smmul
        .align  2
        .type   smmul,%function
smmul:
        smmul   r0, r1, r0
        bx      lr
.Ltmp0:
        .size   smmul, .Ltmp0-smmul