RFA: xscale-elf -mstrict-prototypes

[James Lemke]

Given this source (gcc/testsuite/arm-g4-1.c):
short int addhi3 (short int a, short int b) __attribute__ ((naked));
short int addhi3 (short int a, short int b)
{
    return a + b + (short int)32;
}

The assembler generated (xscale-elf-gcc -O2 -S) is rather poor:
        .file   "arm-g4-1.c"
        .text
        .align  2
        .global addhi3
        .type   addhi3, %function
addhi3:
        @ Naked Function: prologue and epilogue provided by programmer.
        @ args = 0, pretend = 0, frame = 0
        @ frame_needed = 0, uses_anonymous_args = 0
        mov     r1, r1, asl #16
        mov     r0, r0, asl #16
        mov     r1, r1, asr #16
        add     r1, r1, r0, asr #16
        add     r1, r1, #32
        mov     r1, r1, asl #16
        mov     r0, r1, asr #16
        .size   addhi3, .-addhi3
        .ident  "GCC: (GNU) 3.5.0 20040216 (experimental)"

This is because of argument widening even in the presence of a
prototype.  The attached patch adds the option -mstrict-prototypes (off
by default) which suppresses the widening.  So we get (xscale-elf-gcc
-O2 -mstrict-prototypes -S):
        .file   "arm-g4-1.c"
        .text
        .align  2
        .global addhi3
        .type   addhi3, %function
addhi3:
        @ Naked Function: prologue and epilogue provided by programmer.
        @ args = 0, pretend = 0, frame = 0
        @ frame_needed = 0, uses_anonymous_args = 0
        add     r1, r0, r1
        add     r1, r1, #32
        mov     r1, r1, asl #16
        mov     r0, r1, asr #16
        .size   addhi3, .-addhi3
        .ident  "GCC: (GNU) 3.5.0 20040216 (experimental)"


make check-gcc shows no regressions.
Patch is attached.

OK to commit?

Jim.

-- 
James Lemke   jim@wasabisystems.com   Orillia, Ontario
http://www.wasabisystems.com
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