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x86-64-asm: Fix mov im64,rax encoding

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the avoidance of mov im32->reg64 wasn't working when reg64 was rax.
While fixing this also fix instructions which had the REX prefix
hardcoded in opcode and so didn't support extended registers which
would have added another REX prefix.
This commit is contained in:
Michael Matz
2017-02-23 00:16:25 +01:00
parent e209b7dac4
commit 3e4c296eba
3 changed files with 33 additions and 13 deletions
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11
i386-asm.c
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@ -42,6 +42,7 @@
#define OPCT_IS(v,i) (((v) & OPCT_MASK) == (i))
#define OPC_0F 0x100 /* Is secondary map (0x0f prefix) */
#define OPC_48 0x200 /* Always has REX prefix */
#ifdef TCC_TARGET_X86_64
# define OPC_WLQ 0x1000 /* accepts w, l, q or no suffix */
# define OPC_BWLQ (OPC_B | OPC_WLQ) /* accepts b, w, l, q or no suffix */
@ -785,7 +786,7 @@ ST_FUNC void asm_opcode(TCCState *s1, int opcode)
should only be done if we really have an >32bit imm64, and that
is hardcoded. Ignore it here. */
if (pa->opcode == 0xb0 && ops[0].type != OP_IM64
&& ops[1].type == OP_REG64
&& (ops[1].type & OP_REG) == OP_REG64
&& !(pa->instr_type & OPC_0F))
continue;
#endif
@ -901,14 +902,16 @@ ST_FUNC void asm_opcode(TCCState *s1, int opcode)
g(0x66);
#ifdef TCC_TARGET_X86_64
rex64 = 0;
if (s == 3 || (alltypes & OP_REG64)) {
if (pa->instr_type & OPC_48)
rex64 = 1;
else if (s == 3 || (alltypes & OP_REG64)) {
/* generate REX prefix */
int default64 = 0;
for(i = 0; i < nb_ops; i++) {
if (op_type[i] == OP_REG64) {
if (op_type[i] == OP_REG64 && pa->opcode != 0xb8) {
/* If only 64bit regs are accepted in one operand
this is a default64 instruction without need for
REX prefixes. */
REX prefixes, except for movabs(0xb8). */
default64 = 1;
break;
}