target-ppc: Bug Fix: mullw

For 64-bit implementations, the mullw result is the 64 bit product
of the sign-extended least significant 32 bits of the source
registers.

Fix the code to properly sign extend the source operands and produce
a 64 bit product.

Example:
R3 00000000002F37A0
R4 41C33D242F816715
mullw 3,3,4
R3 expected : 0008C3146AE0F020
R3 actual   : 000000006AE0F020 (without this patch)

Signed-off-by: Tom Musta <tommusta@gmail.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
This commit is contained in:
Tom Musta 2014-08-12 08:45:06 -05:00 committed by Alexander Graf
parent f11ebbf8d4
commit 1fa74845f2

View File

@ -1128,9 +1128,20 @@ static void gen_mulhwu(DisasContext *ctx)
/* mullw mullw. */
static void gen_mullw(DisasContext *ctx)
{
#if defined(TARGET_PPC64)
TCGv_i64 t0, t1;
t0 = tcg_temp_new_i64();
t1 = tcg_temp_new_i64();
tcg_gen_ext32s_tl(t0, cpu_gpr[rA(ctx->opcode)]);
tcg_gen_ext32s_tl(t1, cpu_gpr[rB(ctx->opcode)]);
tcg_gen_mul_i64(cpu_gpr[rD(ctx->opcode)], t0, t1);
tcg_temp_free(t0);
tcg_temp_free(t1);
#else
tcg_gen_mul_tl(cpu_gpr[rD(ctx->opcode)], cpu_gpr[rA(ctx->opcode)],
cpu_gpr[rB(ctx->opcode)]);
tcg_gen_ext32s_tl(cpu_gpr[rD(ctx->opcode)], cpu_gpr[rD(ctx->opcode)]);
#endif
if (unlikely(Rc(ctx->opcode) != 0))
gen_set_Rc0(ctx, cpu_gpr[rD(ctx->opcode)]);
}