target/sh4: Rename TCGv variables as manual for ADDV opcode
To easily compare with the SH4 manual, rename:
REG(B11_8) -> Rn
REG(B7_4) -> Rm
t0 -> result
Mention how overflow is calculated.
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Yoshinori Sato <ysato@users.sourceforge.jp>
Message-Id: <20240430163125.77430-4-philmd@linaro.org>
diff --git a/target/sh4/translate.c b/target/sh4/translate.c
index 3e013b7..47c0f34 100644
--- a/target/sh4/translate.c
+++ b/target/sh4/translate.c
@@ -705,16 +705,20 @@
return;
case 0x300f: /* addv Rm,Rn */
{
- TCGv t0, t1, t2;
- t0 = tcg_temp_new();
- tcg_gen_add_i32(t0, REG(B7_4), REG(B11_8));
+ TCGv Rn = REG(B11_8);
+ TCGv Rm = REG(B7_4);
+ TCGv result, t1, t2;
+
+ result = tcg_temp_new();
t1 = tcg_temp_new();
- tcg_gen_xor_i32(t1, t0, REG(B11_8));
t2 = tcg_temp_new();
- tcg_gen_xor_i32(t2, REG(B7_4), REG(B11_8));
+ tcg_gen_add_i32(result, Rm, Rn);
+ /* T = ((Rn ^ Rm) & (Result ^ Rn)) >> 31 */
+ tcg_gen_xor_i32(t1, result, Rn);
+ tcg_gen_xor_i32(t2, Rm, Rn);
tcg_gen_andc_i32(cpu_sr_t, t1, t2);
tcg_gen_shri_i32(cpu_sr_t, cpu_sr_t, 31);
- tcg_gen_mov_i32(REG(B11_8), t0);
+ tcg_gen_mov_i32(Rn, result);
}
return;
case 0x2009: /* and Rm,Rn */