Re: [Qemu-devel] [PATCH] target/arm: Fix sign-extension for SMLAL*
On 9/12/19 8:30 PM, Richard Henderson wrote: > The 32-bit product should be sign-extended, not zero-extended. > > Fixes: ea96b374641b > Reported-by: Laurent Desnogues > Signed-off-by: Richard Henderson Reviewed-by: Philippe Mathieu-Daudé > --- > target/arm/translate.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/target/arm/translate.c b/target/arm/translate.c > index 34bb280e3d..fd2f0e3048 100644 > --- a/target/arm/translate.c > +++ b/target/arm/translate.c > @@ -8045,7 +8045,9 @@ static bool op_smlaxxx(DisasContext *s, arg_ *a, > case 2: > tl = load_reg(s, a->ra); > th = load_reg(s, a->rd); > -t1 = tcg_const_i32(0); > +/* Sign-extend the 32-bit product to 64 bits. */ > +t1 = tcg_temp_new_i32(); > +tcg_gen_sari_i32(t1, t0, 31); > tcg_gen_add2_i32(tl, th, tl, th, t0, t1); > tcg_temp_free_i32(t0); > tcg_temp_free_i32(t1); >
Re: [Qemu-devel] [PATCH] target/arm: Fix sign-extension for SMLAL*
Hello, On Thu, Sep 12, 2019 at 8:31 PM Richard Henderson wrote: > > The 32-bit product should be sign-extended, not zero-extended. > > Fixes: ea96b374641b > Reported-by: Laurent Desnogues > Signed-off-by: Richard Henderson No more failures on my tests. Tested-by: Laurent Desnogues Thanks, Laurent > --- > target/arm/translate.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/target/arm/translate.c b/target/arm/translate.c > index 34bb280e3d..fd2f0e3048 100644 > --- a/target/arm/translate.c > +++ b/target/arm/translate.c > @@ -8045,7 +8045,9 @@ static bool op_smlaxxx(DisasContext *s, arg_ *a, > case 2: > tl = load_reg(s, a->ra); > th = load_reg(s, a->rd); > -t1 = tcg_const_i32(0); > +/* Sign-extend the 32-bit product to 64 bits. */ > +t1 = tcg_temp_new_i32(); > +tcg_gen_sari_i32(t1, t0, 31); > tcg_gen_add2_i32(tl, th, tl, th, t0, t1); > tcg_temp_free_i32(t0); > tcg_temp_free_i32(t1); > -- > 2.17.1 >
[Qemu-devel] [PATCH] target/arm: Fix sign-extension for SMLAL*
The 32-bit product should be sign-extended, not zero-extended. Fixes: ea96b374641b Reported-by: Laurent Desnogues Signed-off-by: Richard Henderson --- target/arm/translate.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/target/arm/translate.c b/target/arm/translate.c index 34bb280e3d..fd2f0e3048 100644 --- a/target/arm/translate.c +++ b/target/arm/translate.c @@ -8045,7 +8045,9 @@ static bool op_smlaxxx(DisasContext *s, arg_ *a, case 2: tl = load_reg(s, a->ra); th = load_reg(s, a->rd); -t1 = tcg_const_i32(0); +/* Sign-extend the 32-bit product to 64 bits. */ +t1 = tcg_temp_new_i32(); +tcg_gen_sari_i32(t1, t0, 31); tcg_gen_add2_i32(tl, th, tl, th, t0, t1); tcg_temp_free_i32(t0); tcg_temp_free_i32(t1); -- 2.17.1
