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Inline assembly and ldm/stm
- From: "Bryce Schober" <bryce dot schober at dynonavionics dot com>
- To: gcc-help at gcc dot gnu dot org
- Date: Mon, 9 Apr 2007 14:04:03 -0700
- Subject: Inline assembly and ldm/stm
So how should I go about wrapping ldm / stm for usage in C land?
I tried:
typedef struct
{
UNS_32 reg[2];
} arm_2_registers_t;
static inline
arm_2_registers_t arm_2_registers_load(
UNS_32 *src_addr_ptr )
{
arm_2_registers_t result;
__asm__ (
"ldmia %0, {%1,%2} \n\t"
: "+r" (src_addr_ptr), "=r" (result.reg[0]), "=r" (result.reg[1])
);
return( result );
}
That seems to work fine until the compiler decides to use registers
for %1 and %2 that aren't in ascending order. I've examined the
assembly constraints and I don't see anything obvious.
--
Bryce Schober