* [PATCH] target/ppc: Fix xvcmp* clearing FI bit
@ 2022-10-05 12:15 Víctor Colombo
2022-10-05 13:51 ` Richard Henderson
2022-10-14 10:25 ` Daniel Henrique Barboza
0 siblings, 2 replies; 3+ messages in thread
From: Víctor Colombo @ 2022-10-05 12:15 UTC (permalink / raw)
To: qemu-devel, qemu-ppc
Cc: clg, danielhb413, david, groug, richard.henderson, victor.colombo,
matheus.ferst, lucas.araujo, leandro.lupori, lucas.coutinho
Vector instructions in general are not supposed to change the FI bit.
However, xvcmp* instructions are calling gen_helper_float_check_status,
which is leading to a cleared FI flag where it should be kept
unchanged.
As helper_float_check_status only affects inexact, overflow and
underflow, and the xvcmp* instructions don't change these flags, this
issue can be fixed by removing the call to helper_float_check_status.
By doing this, the FI bit in FPSCR will be preserved as expected.
Fixes: 00084a25adf ("target/ppc: introduce separate VSX_CMP macro for xvcmp* instructions")
Signed-off-by: Víctor Colombo <victor.colombo@eldorado.org.br>
---
target/ppc/translate/vsx-impl.c.inc | 1 -
1 file changed, 1 deletion(-)
diff --git a/target/ppc/translate/vsx-impl.c.inc b/target/ppc/translate/vsx-impl.c.inc
index 7acdbceec4..e6e5c45ffd 100644
--- a/target/ppc/translate/vsx-impl.c.inc
+++ b/target/ppc/translate/vsx-impl.c.inc
@@ -810,7 +810,6 @@ static void gen_##name(DisasContext *ctx) \
gen_helper_##name(ignored, cpu_env, xt, xa, xb); \
tcg_temp_free_i32(ignored); \
} \
- gen_helper_float_check_status(cpu_env); \
tcg_temp_free_ptr(xt); \
tcg_temp_free_ptr(xa); \
tcg_temp_free_ptr(xb); \
--
2.25.1
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH] target/ppc: Fix xvcmp* clearing FI bit
2022-10-05 12:15 [PATCH] target/ppc: Fix xvcmp* clearing FI bit Víctor Colombo
@ 2022-10-05 13:51 ` Richard Henderson
2022-10-14 10:25 ` Daniel Henrique Barboza
1 sibling, 0 replies; 3+ messages in thread
From: Richard Henderson @ 2022-10-05 13:51 UTC (permalink / raw)
To: Víctor Colombo, qemu-devel, qemu-ppc
Cc: clg, danielhb413, david, groug, matheus.ferst, lucas.araujo,
leandro.lupori, lucas.coutinho
On 10/5/22 05:15, Víctor Colombo wrote:
> Vector instructions in general are not supposed to change the FI bit.
> However, xvcmp* instructions are calling gen_helper_float_check_status,
> which is leading to a cleared FI flag where it should be kept
> unchanged.
> As helper_float_check_status only affects inexact, overflow and
> underflow, and the xvcmp* instructions don't change these flags, this
> issue can be fixed by removing the call to helper_float_check_status.
> By doing this, the FI bit in FPSCR will be preserved as expected.
>
> Fixes: 00084a25adf ("target/ppc: introduce separate VSX_CMP macro for xvcmp* instructions")
> Signed-off-by: Víctor Colombo<victor.colombo@eldorado.org.br>
> ---
> target/ppc/translate/vsx-impl.c.inc | 1 -
> 1 file changed, 1 deletion(-)
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
r~
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] target/ppc: Fix xvcmp* clearing FI bit
2022-10-05 12:15 [PATCH] target/ppc: Fix xvcmp* clearing FI bit Víctor Colombo
2022-10-05 13:51 ` Richard Henderson
@ 2022-10-14 10:25 ` Daniel Henrique Barboza
1 sibling, 0 replies; 3+ messages in thread
From: Daniel Henrique Barboza @ 2022-10-14 10:25 UTC (permalink / raw)
To: Víctor Colombo, qemu-devel, qemu-ppc
Cc: clg, david, groug, richard.henderson, matheus.ferst, lucas.araujo,
leandro.lupori, lucas.coutinho
Queued in gitlab.com/danielhb/qemu/tree/ppc-next. Thanks,
Daniel
On 10/5/22 09:15, Víctor Colombo wrote:
> Vector instructions in general are not supposed to change the FI bit.
> However, xvcmp* instructions are calling gen_helper_float_check_status,
> which is leading to a cleared FI flag where it should be kept
> unchanged.
> As helper_float_check_status only affects inexact, overflow and
> underflow, and the xvcmp* instructions don't change these flags, this
> issue can be fixed by removing the call to helper_float_check_status.
> By doing this, the FI bit in FPSCR will be preserved as expected.
>
> Fixes: 00084a25adf ("target/ppc: introduce separate VSX_CMP macro for xvcmp* instructions")
> Signed-off-by: Víctor Colombo <victor.colombo@eldorado.org.br>
> ---
> target/ppc/translate/vsx-impl.c.inc | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/target/ppc/translate/vsx-impl.c.inc b/target/ppc/translate/vsx-impl.c.inc
> index 7acdbceec4..e6e5c45ffd 100644
> --- a/target/ppc/translate/vsx-impl.c.inc
> +++ b/target/ppc/translate/vsx-impl.c.inc
> @@ -810,7 +810,6 @@ static void gen_##name(DisasContext *ctx) \
> gen_helper_##name(ignored, cpu_env, xt, xa, xb); \
> tcg_temp_free_i32(ignored); \
> } \
> - gen_helper_float_check_status(cpu_env); \
> tcg_temp_free_ptr(xt); \
> tcg_temp_free_ptr(xa); \
> tcg_temp_free_ptr(xb); \
^ permalink raw reply [flat|nested] 3+ messages in thread
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2022-10-05 12:15 [PATCH] target/ppc: Fix xvcmp* clearing FI bit Víctor Colombo
2022-10-05 13:51 ` Richard Henderson
2022-10-14 10:25 ` Daniel Henrique Barboza
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