Changeset 0fe09b09

Timestamp:

08/29/2022 06:57:54 AM (20 months ago)

Author:

Xi Ruoyao <xry111@…>

Branches:

11.2, 11.3, 12.0, 12.1, kea, ken/TL2024, ken/inkscape-core-mods, ken/tuningfonts, lazarus, lxqt, plabs/newcss, plabs/python-mods, python3.11, qt5new, rahul/power-profiles-daemon, renodr/vulkan-addition, trunk, xry111/llvm18, xry111/soup3, xry111/xf86-video-removal

Children:

8e7000b8

Parents:

2e72850

git-author:

Xi Ruoyao <xry111@…> (08/29/2022 06:51:30 AM)

git-committer:

Xi Ruoyao <xry111@…> (08/29/2022 06:57:54 AM)

Message:

js91: SSE2 can be used for GCC + 32-bit if the system is capable

Other workarounds (simply replacing "double_t") leads FP-related tests
to fail. If someone is really running a non-SSE2 system, he/she will
need Clang (maybe ironically as you have to build more things on such
a slow system, but we don't have any other solution).

File:

• general/genlib/js91.xml (modified) (2 diffs)

general/genlib/js91.xml

@@ -101 +101 @@
     <para role="recommended">
       <!-- If clang is installed, it will be used instead of gcc.
-           gcc does not work for 32-bit system:
+           gcc does not work for 32-bit system w/o -msse2 -mfpmath=sse:
            https://bugzilla.mozilla.org/show_bug.cgi?id=1729459 -->
       <xref linkend="llvm"/> (with <application>Clang</application>,
-      required for 32-bit system)
+      required for 32-bit system without SSE2 capability)
     </para>
 
@@ -293 +293 @@
       (by exporting them and unset them after the installation, or simply
       prepending them before the
-      <command>sh ../js/src/configure.in</command> command). Building
-      with GCC on i?86 is currently broken.
-    </para>
-
+      <command>sh ../js/src/configure.in</command> command).  If you are
+      building on a 32-bit system, also see below.
+    </para>
+
+    <para>
+      <option><envar>CXXFLAGS="-msse2 -mfpmath=sse"</envar></option>:
+      Use SSE2 instead of 387 for double-precision floating-point
+      operations.  It's needed by GCC to satisify the expectations of
+      upstream (Mozilla) developers with floating-point arithmatics.
+      Use it if you are building this package on a 32-bit system with
+      GCC (if Clang is not installed or GCC is explicitly specified).
+      Note that this will cause JS to crash on a processor without SSE2
+      capability.  If you are running the system on such an old processor,
+      Clang is strictly needed.  This setting is not needed on 64-bit
+      systems because all 64-bit x86 processors support SSE2 and the 64-bit
+      compilers (both Clang and GCC) use SSE2 by default.
+    </para>
   </sect2>