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author | Richard Henderson <rth@twiddle.net> | 2017-06-05 20:18:54 -0400 |
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committer | Richard Henderson <rth@twiddle.net> | 2017-06-19 11:10:59 -0700 |
commit | 9c39b94f1448770e7e573e9516d2483816785d1b (patch) | |
tree | 49e70fd7120b059a809e4a0363b299bdac340c68 /tcg/arm | |
parent | acb0b292b6d0f49972dc98f742e79ed53973e438 (diff) | |
download | qemu-9c39b94f1448770e7e573e9516d2483816785d1b.zip qemu-9c39b94f1448770e7e573e9516d2483816785d1b.tar.gz qemu-9c39b94f1448770e7e573e9516d2483816785d1b.tar.bz2 |
tcg/arm: Try pc-relative addresses for movi
Signed-off-by: Richard Henderson <rth@twiddle.net>
Diffstat (limited to 'tcg/arm')
-rw-r--r-- | tcg/arm/tcg-target.inc.c | 40 |
1 files changed, 27 insertions, 13 deletions
diff --git a/tcg/arm/tcg-target.inc.c b/tcg/arm/tcg-target.inc.c index fce382f..42370e5 100644 --- a/tcg/arm/tcg-target.inc.c +++ b/tcg/arm/tcg-target.inc.c @@ -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; - - /* 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); + int rot, opc, rn, diff; + + /* 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; } } |