[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH 07/11] cris: avoid write only variables
From: |
Edgar E. Iglesias |
Subject: |
Re: [Qemu-devel] [PATCH 07/11] cris: avoid write only variables |
Date: |
Thu, 7 Oct 2010 13:07:13 +0200 |
User-agent: |
Mutt/1.5.20 (2009-06-14) |
On Thu, Oct 07, 2010 at 12:08:05PM +0200, Markus Armbruster wrote:
> Blue Swirl <address@hidden> writes:
>
> > Compiling with GCC 4.6.0 20100925 produced warnings:
> > /src/qemu/target-cris/op_helper.c: In function 'helper_movl_sreg_reg':
> > /src/qemu/target-cris/op_helper.c:145:8: error: variable 'tlb_v' set
> > but not used [-Werror=unused-but-set-variable]
> > In file included from /src/qemu/target-cris/translate.c:3154:0:
> > /src/qemu/target-cris/translate_v10.c: In function 'dec10_prep_move_m':
> > /src/qemu/target-cris/translate_v10.c:111:22: error: variable 'rd' set
> > but not used [-Werror=unused-but-set-variable]
> >
> > Fix by making the variable declarations and their uses also conditional
> > to debug definition, delete rd.
> >
> > Signed-off-by: Blue Swirl <address@hidden>
> > ---
> > target-cris/op_helper.c | 6 ++++++
> > target-cris/translate_v10.c | 5 ++---
> > 2 files changed, 8 insertions(+), 3 deletions(-)
> >
> > diff --git a/target-cris/op_helper.c b/target-cris/op_helper.c
> > index a60da94..28c79b1 100644
> > --- a/target-cris/op_helper.c
> > +++ b/target-cris/op_helper.c
> > @@ -142,7 +142,9 @@ void helper_movl_sreg_reg (uint32_t sreg, uint32_t reg)
> > uint32_t idx;
> > uint32_t lo, hi;
> > uint32_t vaddr;
> > +#ifdef CRIS_OP_HELPER_DEBUG
> > int tlb_v;
> > +#endif
> >
> > idx = set = env->sregs[SFR_RW_MM_TLB_SEL];
> > set >>= 4;
> > @@ -157,13 +159,17 @@ void helper_movl_sreg_reg (uint32_t sreg, uint32_t
> > reg)
> > vaddr = EXTRACT_FIELD(env->tlbsets[srs-1][set][idx].hi,
> > 13, 31);
> > vaddr <<= TARGET_PAGE_BITS;
> > +#ifdef CRIS_OP_HELPER_DEBUG
> > tlb_v = EXTRACT_FIELD(env->tlbsets[srs-1][set][idx].lo,
> > 3, 3);
> > +#endif
> > env->tlbsets[srs - 1][set][idx].lo = lo;
> > env->tlbsets[srs - 1][set][idx].hi = hi;
> >
> > +#ifdef CRIS_OP_HELPER_DEBUG
> > D_LOG("tlb flush vaddr=%x v=%d pc=%x\n",
> > vaddr, tlb_v, env->pc);
> > +#endif
> > tlb_flush_page(env, vaddr);
> > }
> > }
>
> Could we eliminate the bothersome variable instead?
>
> diff --git a/target-cris/op_helper.c b/target-cris/op_helper.c
> index a60da94..94e3e27 100644
> --- a/target-cris/op_helper.c
> +++ b/target-cris/op_helper.c
> @@ -142,7 +142,6 @@ void helper_movl_sreg_reg (uint32_t sreg, uint32_t reg)
> uint32_t idx;
> uint32_t lo, hi;
> uint32_t vaddr;
> - int tlb_v;
>
> idx = set = env->sregs[SFR_RW_MM_TLB_SEL];
> set >>= 4;
> @@ -157,13 +156,14 @@ void helper_movl_sreg_reg (uint32_t sreg, uint32_t reg)
> vaddr = EXTRACT_FIELD(env->tlbsets[srs-1][set][idx].hi,
> 13, 31);
> vaddr <<= TARGET_PAGE_BITS;
> - tlb_v = EXTRACT_FIELD(env->tlbsets[srs-1][set][idx].lo,
> + D_LOG("tlb flush vaddr=%x v=%d pc=%x\n",
> + vaddr,
> + EXTRACT_FIELD(env->tlbsets[srs-1][set][idx].lo,
> 3, 3);
> + env->pc);
> env->tlbsets[srs - 1][set][idx].lo = lo;
> env->tlbsets[srs - 1][set][idx].hi = hi;
>
> - D_LOG("tlb flush vaddr=%x v=%d pc=%x\n",
> - vaddr, tlb_v, env->pc);
> tlb_flush_page(env, vaddr);
> }
> }
Hi,
Sorry for the late answer.
Markus, I agree that removing tlb_v would have been better than ifdefs,
but i think that the intent I originally had in mind was that there should
not be a need to flush the entry from the QEMU TLB if the old guest
entry was not valid.
The following patch works on my side:
diff --git a/target-cris/op_helper.c b/target-cris/op_helper.c
index a60da94..be9eb06 100644
--- a/target-cris/op_helper.c
+++ b/target-cris/op_helper.c
@@ -164,7 +164,9 @@ void helper_movl_sreg_reg (uint32_t sreg, uint32_t reg)
D_LOG("tlb flush vaddr=%x v=%d pc=%x\n",
vaddr, tlb_v, env->pc);
- tlb_flush_page(env, vaddr);
+ if (tlb_v) {
+ tlb_flush_page(env, vaddr);
+ }
}
}
#endif
The target-cris/translate_v10.c hunk looks good.
Blue, can you incorporate the tlb_v change in your patch set?
Or if you prefer, I can commit that part on my side.
Cheers