From 7b2919a0b4b3e408e5fee0841c8d717e888917de Mon Sep 17 00:00:00 2001 From: "Juha.Riihimaki@nokia.com" Date: Wed, 21 Oct 2009 12:17:38 +0200 Subject: [PATCH] target-arm: optimize thumb 32-bit multiply MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Acked-by: Laurent Desnogues Signed-off-by: Aurelien Jarno --- target-arm/translate.c | 18 +----------------- 1 file changed, 1 insertion(+), 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;