Hi all.
I discovered an optimization error in the current gcc for MIPS.
When I compile the code below with -O2 it clears the code-field just
after setting it. The instructions are mixed up. It works fine with -O1
and -O0.
If the "//" is removed in front of the first printf, it works too.
/Kjeld
--------------- cut here -----------------
#include <stdio.h>
typedef struct rtx_def
{
short code;
int dummy;
} rtx;
void put_code (rtx *rt, short code)
{
register int length;
length = 1;
for (; length >= 0; length--)
((int *) rt)[length] = 0;
// printf("put_code before\n");
rt->code = code;
printf("put_code after, code=%d %d\n", code, rt->code);
}
int main()
{
rtx rt;
put_code(&rt, 5);
printf("gen_rtx, code=%d\n", rt.code);
}
--------------- cut here -----------------
The assembler looks like:
.rdata
.align 2
$LC0:
.ascii "put_code after, code=%d %d\n\000"
.text
.align 2
.globl put_code
.ent put_code
.type put_code,@function
put_code:
.frame $sp,32,$31 # vars= 0, regs= 2/0, args= 16,
extra= 8
.mask 0x90000000,-4
.fmask 0x00000000,0
.set noreorder
.cpload $25
.set reorder
subu $sp,$sp,32
.cprestore 16
move $2,$5
sll $2,$2,16
sra $2,$2,16
move $5,$2
la $3,$LC0
sw $31,28($sp)
sw $28,24($sp)
move $6,$5
sh $2,0($4) <----- sets code field
sw $0,4($4) <----- clears structure
sw $0,0($4) <----- clears structure
move $4,$3
la $25,printf
jal $31,$25
lw $31,28($sp)
#nop
.set noreorder
.set nomacro
j $31
addu $sp,$sp,32
.set macro
.set reorder
.end put_code
