https://gcc.gnu.org/bugzilla/show_bug.cgi?id=43725
Marat Zakirov <m.zakirov at samsung dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |joseph at codesourcery dot com,
| |m.zakirov at samsung dot com
--- Comment #7 from Marat Zakirov <m.zakirov at samsung dot com> ---
Another neon alloc issue.
Code:
#include <arm_neon.h>
#include <inttypes.h>
extern uint16x8x4_t m0;
extern uint16x8x4_t m1;
void foo(uint16_t * in_ptr)
{
uint16x8x4_t t0, t1;
t0 = vld4q_u16((uint16_t *)&in_ptr[0 ]);
t1 = vld4q_u16((uint16_t *)&in_ptr[64]);
t0.val[0] *= 333;
t0.val[1] *= 333;
t0.val[2] *= 333;
t0.val[3] *= 333;
t1.val[0] *= 333;
t1.val[1] *= 333;
t1.val[2] *= 333;
t1.val[3] *= 333;
m0 = t0;
m1 = t1;
}
Asm file:
.vsave {d8, d9, d10, d11, d12, d13, d14, d15}
add r1, r0, #160
vld4.16 {d8, d10, d12, d14}, [r0]
add r0, r0, #32
.pad #64
sub sp, sp, #64
vld4.16 {d16, d18, d20, d22}, [r2]
movw r3, #:lower16:m1
movw r2, #:lower16:m0
vldr d6, .L3
vldr d7, .L3+8
movt r3, #:upper16:m1
movt r2, #:upper16:m0
vld4.16 {d9, d11, d13, d15}, [r0]
vld4.16 {d17, d19, d21, d23}, [r1]
vmul.i16 q12, q3, q4
vstmia sp, {d16-d23} <<< *
vld1.64 {d4-d5}, [sp:64] <<< *
vmul.i16 q13, q3, q5 <<< **
vmul.i16 q9, q3, q9
vmul.i16 q14, q3, q6 <<< **
vmul.i16 q10, q3, q10
vmul.i16 q8, q3, q2 <<< **, ***
vmul.i16 q15, q3, q7 <<< **
vmul.i16 q11, q3, q11
vstmia r2, {d24-d31}
vstmia r3, {d16-d23}
add sp, sp, #64
@ sp needed
fldmfdd sp!, {d8-d15}
bx lr
So my qustion are:
1) Why do we need * and why compiler used q2 in *** ?
2) Why compiler didn't reuse registers q5,q6,q2,q7 in ** ?
Command line:
cc1 -quiet -v t.c -quiet -dumpbase t.c -mfpu=neon -mcpu=cortex-a15
-mfloat-abi=softfp -marm -mtls-dialect=gnu -auxbase-strip t.s -O3
-Wno-error=unused-local-typedefs -version -fdump-tree-all -fdump-rtl-all
-funwind-tables -o t.s
gcc version = 4.10.0
--build=x86_64-pc-linux-gnu
--host=x86_64-pc-linux-gnu
--target=arm-v7a15v5r2-linux-gnueabi
--Marat
