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| author | Juha.Riihimaki@nokia.com <Juha.Riihimaki@nokia.com> | 2009-10-21 12:17:38 +0200 |
|---|---|---|
| committer | Aurelien Jarno <aurelien@aurel32.net> | 2009-10-23 17:22:13 +0200 |
| commit | 7b2919a0b4b3e408e5fee0841c8d717e888917de (patch) | |
| tree | df7ff7a06a1b44a2f069bef54b966c2293bffe72 | |
| parent | b75263d6533c2ffa60bee16525d9908249e79541 (diff) | |
| download | qemu-7b2919a0b4b3e408e5fee0841c8d717e888917de.tar.gz qemu-7b2919a0b4b3e408e5fee0841c8d717e888917de.tar.bz2 qemu-7b2919a0b4b3e408e5fee0841c8d717e888917de.zip | |
target-arm: optimize thumb 32-bit multiply
Current implementation of thumb mul instruction is implemented as a
32x32->64 multiply which then uses only 32 least significant bits of
the result. Replace that with a simple 32x32->32 multiply.
Signed-off-by: Juha Riihimäki <juha.riihimaki@nokia.com>
Acked-by: Laurent Desnogues <laurent.desnogues@gmail.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
| -rw-r--r-- | target-arm/translate.c | 18 |
1 files changed, 1 insertions, 17 deletions
diff --git a/target-arm/translate.c b/target-arm/translate.c index 813f661ca5..9d13d42ab3 100644 --- a/target-arm/translate.c +++ b/target-arm/translate.c @@ -310,22 +310,6 @@ static TCGv_i64 gen_muls_i64_i32(TCGv a, TCGv b) return tmp1; } -/* Unsigned 32x32->64 multiply. */ -static void gen_mull(TCGv a, TCGv b) -{ - TCGv_i64 tmp1 = tcg_temp_new_i64(); - TCGv_i64 tmp2 = tcg_temp_new_i64(); - - tcg_gen_extu_i32_i64(tmp1, a); - tcg_gen_extu_i32_i64(tmp2, b); - tcg_gen_mul_i64(tmp1, tmp1, tmp2); - tcg_temp_free_i64(tmp2); - tcg_gen_trunc_i64_i32(a, tmp1); - tcg_gen_shri_i64(tmp1, tmp1, 32); - tcg_gen_trunc_i64_i32(b, tmp1); - tcg_temp_free_i64(tmp1); -} - /* Signed 32x32->64 multiply. */ static void gen_imull(TCGv a, TCGv b) { @@ -8363,7 +8347,7 @@ static void disas_thumb_insn(CPUState *env, DisasContext *s) gen_logic_CC(tmp); break; case 0xd: /* mul */ - gen_mull(tmp, tmp2); + tcg_gen_mul_i32(tmp, tmp, tmp2); if (!s->condexec_mask) gen_logic_CC(tmp); break; |