xemu-project/xemu
1
0
Fork 0
mirror of https://github.com/xemu-project/xemu.git synced 2024-11-23 11:39:53 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

tcg/arm: Try pc-relative addresses for movi

Browse Source 
Signed-off-by: Richard Henderson <rth@twiddle.net>
This commit is contained in:
Richard Henderson 2017-06-05 20:18:54 -04:00
parent acb0b292b6
commit 9c39b94f14
1 changed files with 26 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

38
tcg/arm/tcg-target.inc.c
View File

@ -418,23 +418,37 @@ static inline void tcg_out_dat_imm(TCGContext *s,
static void tcg_out_movi32(TCGContext *s, int cond, int rd, uint32_t arg)
{
int rot, opc, rn;
int rot, opc, rn, diff;
/* For armv7, make sure not to use movw+movt when mov/mvn would do.
Speed things up by only checking when movt would be required.
Prior to armv7, have one go at fully rotated immediates before
doing the decomposition thing below. */
if (!use_armv7_instructions || (arg & 0xffff0000)) {
rot = encode_imm(arg);
/* Check a single MOV/MVN before anything else. */
rot = encode_imm(arg);
if (rot >= 0) {
tcg_out_dat_imm(s, cond, ARITH_MOV, rd, 0,
rotl(arg, rot) | (rot << 7));
return;
}
rot = encode_imm(~arg);
if (rot >= 0) {
tcg_out_dat_imm(s, cond, ARITH_MVN, rd, 0,
rotl(~arg, rot) | (rot << 7));
return;
}
/* Check for a pc-relative address. This will usually be the TB,
or within the TB, which is immediately before the code block. */
diff = arg - ((intptr_t)s->code_ptr + 8);
if (diff >= 0) {
rot = encode_imm(diff);
if (rot >= 0) {
tcg_out_dat_imm(s, cond, ARITH_MOV, rd, 0,
rotl(arg, rot) | (rot << 7));
tcg_out_dat_imm(s, cond, ARITH_ADD, rd, TCG_REG_PC,
rotl(diff, rot) | (rot << 7));
return;
}
rot = encode_imm(~arg);
} else {
rot = encode_imm(-diff);
if (rot >= 0) {
tcg_out_dat_imm(s, cond, ARITH_MVN, rd, 0,
rotl(~arg, rot) | (rot << 7));
tcg_out_dat_imm(s, cond, ARITH_SUB, rd, TCG_REG_PC,
rotl(-diff, rot) | (rot << 7));
return;
}
}