* [Qemu-devel] [PATCH] target/hppa: fix PSW Q bit behaviour to match hardware
@ 2019-01-29 19:14 Sven Schnelle
2019-02-06 6:07 ` Richard Henderson
0 siblings, 1 reply; 2+ messages in thread
From: Sven Schnelle @ 2019-01-29 19:14 UTC (permalink / raw)
To: qemu-devel; +Cc: deller, Sven Schnelle, Richard Henderson
PA-RISC specification says: "Setting the PSW Q-bit, PSW{28}, to 1
with this instruction, if it was not already 1, is an undefined
operation." However, at least HP-UX 10.20 sets the Q bit from 0 to 1
with the SSM instruction. Tested this both on HP9000/712 and
HP9000/785/C3750, both machines set the Q bit from 0 to 1 without
exception. This makes HP-UX 10.20 progress a little bit further.
Signed-off-by: Sven Schnelle <svens@stackframe.org>
---
target/hppa/op_helper.c | 5 -----
1 file changed, 5 deletions(-)
diff --git a/target/hppa/op_helper.c b/target/hppa/op_helper.c
index 912e8d5be4..3adcfd8976 100644
--- a/target/hppa/op_helper.c
+++ b/target/hppa/op_helper.c
@@ -665,11 +665,6 @@ void HELPER(reset)(CPUHPPAState *env)
target_ureg HELPER(swap_system_mask)(CPUHPPAState *env, target_ureg nsm)
{
target_ulong psw = env->psw;
- /* ??? On second reading this condition simply seems
- to be undefined rather than a diagnosed trap. */
- if (nsm & ~psw & PSW_Q) {
- hppa_dynamic_excp(env, EXCP_ILL, GETPC());
- }
env->psw = (psw & ~PSW_SM) | (nsm & PSW_SM);
return psw & PSW_SM;
}
--
2.20.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [Qemu-devel] [PATCH] target/hppa: fix PSW Q bit behaviour to match hardware
2019-01-29 19:14 [Qemu-devel] [PATCH] target/hppa: fix PSW Q bit behaviour to match hardware Sven Schnelle
@ 2019-02-06 6:07 ` Richard Henderson
0 siblings, 0 replies; 2+ messages in thread
From: Richard Henderson @ 2019-02-06 6:07 UTC (permalink / raw)
To: Sven Schnelle, qemu-devel; +Cc: deller, Richard Henderson
On 1/29/19 7:14 PM, Sven Schnelle wrote:
> PA-RISC specification says: "Setting the PSW Q-bit, PSW{28}, to 1
> with this instruction, if it was not already 1, is an undefined
> operation." However, at least HP-UX 10.20 sets the Q bit from 0 to 1
> with the SSM instruction. Tested this both on HP9000/712 and
> HP9000/785/C3750, both machines set the Q bit from 0 to 1 without
> exception. This makes HP-UX 10.20 progress a little bit further.
>
> Signed-off-by: Sven Schnelle <svens@stackframe.org>
> ---
> target/hppa/op_helper.c | 5 -----
> 1 file changed, 5 deletions(-)
Queued, with much of this text copied into a comment in the code.
r~
^ permalink raw reply [flat|nested] 2+ messages in thread
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2019-01-29 19:14 [Qemu-devel] [PATCH] target/hppa: fix PSW Q bit behaviour to match hardware Sven Schnelle
2019-02-06 6:07 ` Richard Henderson
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