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Unaligned loader: Support l16si

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This commit is contained in:
Angus Gratton 2015-08-11 15:03:53 +10:00
parent 773a046dc3
commit 8ea4ae27e2
2 changed files with 30 additions and 2 deletions
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20
core/exception_vectors.S
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@ -302,6 +302,8 @@ UserLoadStoreExceptionHandler:
movi a4, 0x001002 /* l16ui opcode after masking */
beq a3, a4, .Lcan_fix_16bit
movi a4, 0x009002 /* l16si opcode after masking */
beq a3, a4, .Lcan_fix_16bit_signed
.Lcant_fix:
/* not an l8ui or an l16ui, or not in the instruction space, so bomb out
TODO: the exception dump will have some wrong values in it */
@ -310,6 +312,9 @@ TODO: the exception dump will have some wrong values in it */
call0 printf
call0 sdk_user_fatal_exception_handler
.Lcan_fix_16bit_signed:
movi a5, 0x7FFF
j .Lcan_fix
.Lcan_fix_16bit:
movi a5, 0xFFFF
j .Lcan_fix
@ -334,11 +339,15 @@ TODO: the exception dump will have some wrong values in it */
l32i a3, a3, 0 /* perform the actual read */
srl a3, a3 /* shift right correct distance */
and a3, a3, a5 /* mask off bits we need for an l8/l16 */
and a4, a3, a5 /* mask off bits we need for an l8/l16 */
bbci a5, 15, .Lextend_sign
.Lafter_extend_sign:
/* a4 holds the correctly read value */
/* write read value to register slot */
add a5, sp, a2
s32i a3, a5, 0
s32i a4, a5, 0
/* Footer*/
//Increment PC
@ -367,6 +376,13 @@ TODO: the exception dump will have some wrong values in it */
addi sp, sp, 0x40
rfe
.Lextend_sign: /* apply 16-bit sign extension if necessary
a3 holds raw value, a4 holds masked */
bbci a3, 15, .Lafter_extend_sign /* sign bit not set, do nothing */
movi a3, (1<<31)
or a4, a3, a4 /* set sign bit */
j .Lafter_extend_sign
.global _xt_user_exit
.type _xt_user_exit, @function
_xt_user_exit: