Revert "Always build with SSE2 support & display an error if not available"

application/palemoon/app/Makefile.in

@@ -33,14 +33,6 @@ NSDISTMODE = copy
 
 include $(topsrcdir)/config/config.mk
 
-# If we are trying to show an error dialog about the lack of SSE2 support,
-# make sure that code itself doesn't use SSE2.
-ifdef MOZ_LINUX_SSE2_STARTUP_ERROR
-CXXFLAGS := $(filter-out -march=% -msse2 -mfpmath=sse,$(CXXFLAGS))
-CXX := $(filter-out -march=% -msse2 -mfpmath=sse,$(CXX))
-CXXFLAGS += -msse -mno-sse2 -mfpmath=387
-endif
-
 ifeq ($(OS_ARCH),WINNT)
 # Rebuild firefox.exe if the manifest changes - it's included by splash.rc.
 # (this dependency should really be just for firefox.exe, not other targets)

application/palemoon/app/moz.build

@@ -68,6 +68,3 @@ if CONFIG['MOZ_LINKER']:
 
 if CONFIG['HAVE_CLOCK_MONOTONIC']:
     OS_LIBS += CONFIG['REALTIME_LIBS']
-
-if CONFIG['MOZ_LINUX_SSE2_STARTUP_ERROR']:
-    DEFINES['MOZ_LINUX_SSE2_STARTUP_ERROR'] = True

application/palemoon/app/nsBrowserApp.cpp

@@ -40,51 +40,6 @@
 #include "mozilla/Telemetry.h"
 #include "mozilla/WindowsDllBlocklist.h"
 
-#ifdef MOZ_LINUX_SSE2_STARTUP_ERROR
-#include <cpuid.h>
-#include "mozilla/Unused.h"
-
-static bool
-IsSSE2Available()
-{
-  // The rest of the app has been compiled to assume that SSE2 is present
-  // unconditionally, so we can't use the normal copy of SSE.cpp here.
-  // Since SSE.cpp caches the results and we need them only transiently,
-  // instead of #including SSE.cpp here, let's just inline the specific check
-  // that's needed.
-  unsigned int level = 1u;
-  unsigned int eax, ebx, ecx, edx;
-  unsigned int bits = (1u<<26);
-  unsigned int max = __get_cpuid_max(0, nullptr);
-  if (level > max) {
-    return false;
-  }
-  __cpuid_count(level, 0, eax, ebx, ecx, edx);
-  return (edx & bits) == bits;
-}
-
-static const char sSSE2Message[] =
-    "This browser version requires a processor with the SSE2 instruction "
-    "set extension.\n";
-
-__attribute__((constructor))
-static void
-SSE2Check()
-{
-  if (IsSSE2Available()) {
-    return;
-  }
-  // Using write() in order to avoid jemalloc-based buffering. Ignoring return
-  // values, since there isn't much we could do on failure and there is no
-  // point in trying to recover from errors.
-  MOZ_UNUSED(write(STDERR_FILENO,
-                   sSSE2Message,
-                   MOZ_ARRAY_LENGTH(sSSE2Message) - 1));
-  // _exit() instead of exit() to avoid running the usual "at exit" code.
-  _exit(255);
-}
-#endif
-
 #if !defined(MOZ_WIDGET_COCOA) && !defined(MOZ_WIDGET_ANDROID)
 #define MOZ_BROWSER_CAN_BE_CONTENTPROC
 #include "../../ipc/contentproc/plugin-container.cpp"

application/palemoon/confvars.sh

@@ -98,11 +98,6 @@ if test "$OS_ARCH" = "WINNT" -o \
   MOZ_BUNDLED_FONTS=1
 fi
 
-# Display an error on non-SSE2 Linux systems
-if test "$OS_ARCH" = "Linux"; then
-  MOZ_LINUX_SSE2_STARTUP_ERROR=1
-fi
-
 # Short-circuit a few services to be removed
 MOZ_MAINTENANCE_SERVICE=
 MOZ_SERVICES_HEALTHREPORT=

browser/app/Makefile.in

@@ -23,14 +23,6 @@ NSDISTMODE = copy
 
 include $(topsrcdir)/config/config.mk
 
-# If we are trying to show an error dialog about the lack of SSE2 support,
-# make sure that code itself doesn't use SSE2.
-ifdef MOZ_LINUX_SSE2_STARTUP_ERROR
-CXXFLAGS := $(filter-out -march=% -msse2 -mfpmath=sse,$(CXXFLAGS))
-CXX := $(filter-out -march=% -msse2 -mfpmath=sse,$(CXX))
-CXXFLAGS += -msse -mno-sse2 -mfpmath=387
-endif
-
 ifeq ($(OS_ARCH),WINNT)
 # Rebuild firefox.exe if the manifest changes - it's included by splash.rc.
 # (this dependency should really be just for firefox.exe, not other targets)

browser/app/moz.build

@@ -70,10 +70,6 @@ if CONFIG['HAVE_CLOCK_MONOTONIC']:
 if CONFIG['MOZ_GPSD']:
     DEFINES['MOZ_GPSD'] = True
 
-
-if CONFIG['MOZ_LINUX_SSE2_STARTUP_ERROR']:
-    DEFINES['MOZ_LINUX_SSE2_STARTUP_ERROR'] = True
-
 for icon in ('firefox', 'document', 'newwindow', 'newtab', 'pbmode'):
     DEFINES[icon.upper() + '_ICO'] = '"%s/dist/branding/%s.ico"' % (
         TOPOBJDIR, icon)

browser/app/nsBrowserApp.cpp

@@ -40,51 +40,6 @@
 #include "mozilla/Telemetry.h"
 #include "mozilla/WindowsDllBlocklist.h"
 
-#ifdef MOZ_LINUX_SSE2_STARTUP_ERROR
-#include <cpuid.h>
-#include "mozilla/Unused.h"
-
-static bool
-IsSSE2Available()
-{
-  // The rest of the app has been compiled to assume that SSE2 is present
-  // unconditionally, so we can't use the normal copy of SSE.cpp here.
-  // Since SSE.cpp caches the results and we need them only transiently,
-  // instead of #including SSE.cpp here, let's just inline the specific check
-  // that's needed.
-  unsigned int level = 1u;
-  unsigned int eax, ebx, ecx, edx;
-  unsigned int bits = (1u<<26);
-  unsigned int max = __get_cpuid_max(0, nullptr);
-  if (level > max) {
-    return false;
-  }
-  __cpuid_count(level, 0, eax, ebx, ecx, edx);
-  return (edx & bits) == bits;
-}
-
-static const char sSSE2Message[] =
-    "This browser version requires a processor with the SSE2 instruction "
-    "set extension.\n";
-
-__attribute__((constructor))
-static void
-SSE2Check()
-{
-  if (IsSSE2Available()) {
-    return;
-  }
-  // Using write() in order to avoid jemalloc-based buffering. Ignoring return
-  // values, since there isn't much we could do on failure and there is no
-  // point in trying to recover from errors.
-  MOZ_UNUSED(write(STDERR_FILENO,
-                   sSSE2Message,
-                   MOZ_ARRAY_LENGTH(sSSE2Message) - 1));
-  // _exit() instead of exit() to avoid running the usual "at exit" code.
-  _exit(255);
-}
-#endif
-
 #if !defined(MOZ_WIDGET_COCOA) && !defined(MOZ_WIDGET_ANDROID)
 #define MOZ_BROWSER_CAN_BE_CONTENTPROC
 #include "../../ipc/contentproc/plugin-container.cpp"

browser/confvars.sh

@@ -18,11 +18,6 @@ if test "$OS_ARCH" = "WINNT"; then
   MOZ_MAINTENANCE_SERVICE=
 fi
 
-# Display an error on non-SSE2 Linux systems
-if test "$OS_ARCH" = "Linux"; then
-  MOZ_LINUX_SSE2_STARTUP_ERROR=1
-fi
-
 # For Basilisk we want to use 52.9.YYYY.MM.DD as MOZ_APP_VERSION in release
 # builds so add-on developers have something to target while maintaining
 # Firefox compatiblity.

build/autoconf/compiler-opts.m4

@@ -176,8 +176,8 @@ if test "$GNU_CC"; then
         CFLAGS="$CFLAGS -ffunction-sections -fdata-sections"
         CXXFLAGS="$CXXFLAGS -ffunction-sections -fdata-sections"
     fi
-    CFLAGS="$CFLAGS -fno-math-errno -msse2 -mfpmath=sse"
+    CFLAGS="$CFLAGS -fno-math-errno"
-    CXXFLAGS="$CXXFLAGS -fno-exceptions -fno-math-errno -msse2 -mfpmath=sse"
+    CXXFLAGS="$CXXFLAGS -fno-exceptions -fno-math-errno"
 
     if test -z "$CLANG_CC"; then
         case "$CC_VERSION" in

old-configure.in

@@ -4884,12 +4884,6 @@ if test "$USE_FC_FREETYPE"; then
     fi
 fi
 
-dnl ========================================================
-dnl Check if we need the Linux SSE2 error dialog
-dnl ========================================================
-
-AC_SUBST(MOZ_LINUX_SSE2_STARTUP_ERROR)
-
 dnl ========================================================
 dnl Check for pixman and cairo
 dnl ========================================================