From: Aurelien Jarno <aurelien@aurel32.net>
To: Richard Henderson <rth@twiddle.net>
Cc: peter.maydell@linaro.org, qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [PATCH 10/17] tcg/optimize: do not remember garbage high bits for 32-bit ops
Date: Tue, 18 Aug 2015 10:35:06 +0200 [thread overview]
Message-ID: <20150818083506.GA20101@aurel32.net> (raw)
In-Reply-To: <1439840320-20897-11-git-send-email-rth@twiddle.net>
On 2015-08-17 12:38, Richard Henderson wrote:
> From: Aurelien Jarno <aurelien@aurel32.net>
>
> Now that we have real size changing ops, we don't need to mark high
> bits of the destination as garbage. The goal of the optimizer is to
> predict the value of the temps (and not of the registers) and do
> simplifications when possible. The problem there is therefore not the
> fact that those bits are not counted as garbage, but that a size
> changing op is replaced by a move.
>
> This patch is basically a revert of 24666baf, including the changes that
> have been made since then.
>
> Cc: Richard Henderson <rth@twiddle.net>
> Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
> ---
> tcg/optimize.c | 41 +++++++++++------------------------------
> 1 file changed, 11 insertions(+), 30 deletions(-)
Self NACK. This patch breaks things given !(def->flags & TCG_OPF_64BIT)
doesn't necessary means 32-bit result, at least in the case of the call
opcode.
I'll try to send an updated patch which handles that correctly in the
next days (and catch up on other QEMU things), I am currently busy with
other free software stuff.
--
Aurelien Jarno GPG: 4096R/1DDD8C9B
aurelien@aurel32.net http://www.aurel32.net
next prev parent reply other threads:[~2015-08-18 8:35 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-08-17 19:38 [Qemu-devel] [PATCH 00/17] queued tcg improvements Richard Henderson
2015-08-17 19:38 ` [Qemu-devel] [PATCH 01/17] tcg/optimize: fix constant signedness Richard Henderson
2015-08-17 19:38 ` [Qemu-devel] [PATCH 02/17] tcg/optimize: optimize temps tracking Richard Henderson
2015-08-17 19:38 ` [Qemu-devel] [PATCH 03/17] tcg/optimize: add temp_is_const and temp_is_copy functions Richard Henderson
2015-08-17 19:38 ` [Qemu-devel] [PATCH 04/17] tcg/optimize: track const/copy status separately Richard Henderson
2015-08-17 19:38 ` [Qemu-devel] [PATCH 05/17] tcg/optimize: allow constant to have copies Richard Henderson
2015-08-17 19:38 ` [Qemu-devel] [PATCH 06/17] tcg: rename trunc_shr_i32 into trunc_shr_i64_i32 Richard Henderson
2015-08-17 19:38 ` [Qemu-devel] [PATCH 07/17] tcg: don't abuse TCG type in tcg_gen_trunc_shr_i64_i32 Richard Henderson
2015-08-17 19:38 ` [Qemu-devel] [PATCH 08/17] tcg: implement real ext_i32_i64 and extu_i32_i64 ops Richard Henderson
2015-08-17 19:51 ` Claudio Fontana
2015-08-17 19:38 ` [Qemu-devel] [PATCH 09/17] tcg/optimize: add optimizations for " Richard Henderson
2015-08-17 19:38 ` [Qemu-devel] [PATCH 10/17] tcg/optimize: do not remember garbage high bits for 32-bit ops Richard Henderson
2015-08-18 8:35 ` Aurelien Jarno [this message]
2015-08-17 19:38 ` [Qemu-devel] [PATCH 11/17] tcg: update README about size changing ops Richard Henderson
2015-08-17 19:38 ` [Qemu-devel] [PATCH 12/17] tcg: Split trunc_shr_i32 opcode into extr[lh]_i64_i32 Richard Henderson
2015-08-17 19:38 ` [Qemu-devel] [PATCH 14/17] tcg/i386: use softmmu fast path for unaligned accesses Richard Henderson
2015-08-17 19:38 ` [Qemu-devel] [PATCH 15/17] tcg/ppc: Improve unaligned load/store handling on 64-bit backend Richard Henderson
2015-08-17 19:38 ` [Qemu-devel] [PATCH 16/17] tcg/s390: Use softmmu fast path for unaligned accesses Richard Henderson
2015-08-17 19:38 ` [Qemu-devel] [PATCH 17/17] tcg/aarch64: " Richard Henderson
2015-08-17 20:06 ` [Qemu-devel] [PATCH 00/17] queued tcg improvements Richard Henderson
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