From: Paolo Bonzini <pbonzini@redhat.com>
To: qemu-devel@nongnu.org
Cc: richard.henderson@linaro.org
Subject: [PATCH] tcg/i386: convert add/sub of 128 to sub/add of -128
Date: Thu, 21 Dec 2023 14:43:55 +0100 [thread overview]
Message-ID: <20231221134355.35304-1-pbonzini@redhat.com> (raw)
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
tcg/i386/tcg-target.c.inc | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/tcg/i386/tcg-target.c.inc b/tcg/i386/tcg-target.c.inc
index a83f8aab304..4e9f372d4fd 100644
--- a/tcg/i386/tcg-target.c.inc
+++ b/tcg/i386/tcg-target.c.inc
@@ -1332,7 +1332,11 @@ static void tgen_arithi(TCGContext *s, int c, int r0,
return;
}
- if (c == ARITH_AND) {
+ if ((c == ARITH_ADD || c == ARITH_SUB) && val == 128) {
+ /* Facilitate using an 8-bit immediate. */
+ c ^= ARITH_ADD ^ ARITH_SUB;
+ val = -128;
+ } else if (c == ARITH_AND) {
if (TCG_TARGET_REG_BITS == 64) {
if (val == 0xffffffffu) {
tcg_out_ext32u(s, r0, r0);
--
2.43.0
next reply other threads:[~2023-12-21 13:44 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-12-21 13:43 Paolo Bonzini [this message]
2023-12-27 20:13 ` [PATCH] tcg/i386: convert add/sub of 128 to sub/add of -128 Richard Henderson
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20231221134355.35304-1-pbonzini@redhat.com \
--to=pbonzini@redhat.com \
--cc=qemu-devel@nongnu.org \
--cc=richard.henderson@linaro.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).