http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47025
Summary: Dead stores in varadic functions not eliminated
Product: gcc
Version: 4.5.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
AssignedTo: unassig...@gcc.gnu.org
ReportedBy: j...@beniston.com
If I compile a varadic function such as this:
double d;
void func(int a, ...)
{
va_list ap;
va_start(ap, a);
d = va_arg(ap, double);
va_end(ap);
}
with:
mips-elf-gcc test.c -O2 -S -mhard-float -march=m4k -mabi=eabi
The stores of register arguments on to the stack are not eliminated, even if
not used. Eg:
func:
.frame $sp,80,$31 # vars= 16, regs= 0/0, args= 0, gp= 0
.mask 0x00000000,0
.fmask 0x00000000,0
.set noreorder
.set nomacro
addiu $sp,$sp,-80
addiu $2,$sp,80
sw $2,0($sp)
sw $2,4($sp)
addiu $2,$sp,48
sw $2,8($sp)
li $2,28
sb $2,12($sp)
li $2,24
sw $5,52($sp) # redundant stores
sw $6,56($sp)
sw $7,60($sp)
sw $8,64($sp)
sw $9,68($sp)
sw $10,72($sp)
sw $11,76($sp)
sdc1 $f12,16($sp)
sdc1 $f14,24($sp)
sdc1 $f16,32($sp)
sdc1 $f18,40($sp)
sb $2,13($sp)
sdc1 $f12,%gp_rel(d)($28)
j $31
addiu $sp,$sp,80
