From: Mark Wielaard <mark@klomp.org>
Date: Tue, 28 May 2019 15:20:31 +0000 (+0200)
Subject: Fix coding nit in x86amd64g_calculate_FXTRACT.
X-Git-Tag: VALGRIND_3_16_0~277
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a82b92e2ebfdd84ac953b05f679c67834942062b;p=thirdparty%2Fvalgrind.git

Fix coding nit in x86amd64g_calculate_FXTRACT.

The current code "return getExp ? posInf : posInf;" looks like a typo.
But when the argument is positive infinity then both the significand
and the exponent are positive infinity (there is a fxtract testcase that
checks that). So no need to check getExp. Just always return posInf
if arg == posInf, but add a comment explaining why.
---

diff --git a/VEX/priv/guest_generic_x87.c b/VEX/priv/guest_generic_x87.c
index 1e76395d52..85ebebdc77 100644
--- a/VEX/priv/guest_generic_x87.c
+++ b/VEX/priv/guest_generic_x87.c
@@ -453,7 +453,7 @@ ULong x86amd64g_calculate_FXTRACT ( ULong arg, HWord getExp )
 
    /* Mimic Core i5 behaviour for special cases. */
    if (arg == posInf)
-      return getExp ? posInf : posInf;
+      return posInf; /* Both significand and exponent are posInf. */
    if (arg == negInf)
       return getExp ? posInf : negInf;
    if ((arg & nanMask) == nanMask)