From 702d89aec2bd5a4c587988b56ec7736866a21a68 Mon Sep 17 00:00:00 2001
From: Lepton Wu <lepton@chromium.org>
Date: Mon, 29 Jul 2019 12:37:41 -0700
Subject: [PATCH] Revert "mesa: Enable asm unconditionally, now that
 gen_matypes is gone."

This reverts commit 20294dceebc23236e33b22578245f7e6f41b6997.
---
 Android.common.mk                   |  3 +
 Android.mk                          |  7 +++
 meson.build                         | 94 +++++++++++++++++++----------
 meson_options.txt                   |  6 ++
 src/mesa/Android.libmesa_dricore.mk |  2 +
 src/mesa/Android.libmesa_st_mesa.mk |  2 +
 6 files changed, 81 insertions(+), 33 deletions(-)

diff --git a/Android.common.mk b/Android.common.mk
index 825b60381d0..327f13f5a38 100644
--- a/Android.common.mk
+++ b/Android.common.mk
@@ -103,9 +103,12 @@ ifeq ($(shell test $(PLATFORM_SDK_VERSION) -ge 26 && echo true),true)
 LOCAL_CFLAGS += -DHAVE_SYS_SHM_H
 endif
 
+ifeq ($(strip $(MESA_ENABLE_ASM)),true)
 ifeq ($(TARGET_ARCH),x86)
 LOCAL_CFLAGS += \
 	-DUSE_X86_ASM
+
+endif
 endif
 ifeq ($(ARCH_ARM_HAVE_NEON),true)
 LOCAL_CFLAGS_arm += -DUSE_ARM_ASM
diff --git a/Android.mk b/Android.mk
index 8d274e56836..5fe028c6d19 100644
--- a/Android.mk
+++ b/Android.mk
@@ -83,6 +83,13 @@ endif
 
 $(foreach d, $(MESA_BUILD_CLASSIC) $(MESA_BUILD_GALLIUM), $(eval $(d) := true))
 
+# host and target must be the same arch to generate matypes.h
+ifeq ($(TARGET_ARCH),$(HOST_ARCH))
+MESA_ENABLE_ASM := true
+else
+MESA_ENABLE_ASM := false
+endif
+
 ifneq ($(filter true, $(HAVE_GALLIUM_RADEONSI)),)
 MESA_ENABLE_LLVM := true
 endif
diff --git a/meson.build b/meson.build
index f4c013a5319..6483970029d 100644
--- a/meson.build
+++ b/meson.build
@@ -49,6 +49,7 @@ with_vulkan_icd_dir = get_option('vulkan-icd-dir')
 with_tests = get_option('build-tests')
 with_valgrind = get_option('valgrind')
 with_libunwind = get_option('libunwind')
+with_asm = get_option('asm')
 with_glx_read_only_text = get_option('glx-read-only-text')
 with_glx_direct = get_option('glx-direct')
 with_osmesa = get_option('osmesa')
@@ -978,41 +979,68 @@ endif
 
 # TODO: shared/static? Is this even worth doing?
 
+# When cross compiling we generally need to turn off the use of assembly,
+# because mesa's assembly relies on building an executable for the host system,
+# and running it to get information about struct sizes. There is at least one
+# case of cross compiling where we can use asm, and that's x86_64 -> x86 when
+# host OS == build OS, since in that case the build machine can run the host's
+# binaries.
+if with_asm and meson.is_cross_build()
+  if build_machine.system() != host_machine.system()
+    # TODO: It may be possible to do this with an exe_wrapper (like wine).
+    message('Cross compiling from one OS to another, disabling assembly.')
+    with_asm = false
+  elif not (build_machine.cpu_family().startswith('x86') and host_machine.cpu_family() == 'x86')
+    # FIXME: Gentoo always sets -m32 for x86_64 -> x86 builds, resulting in an
+    # x86 -> x86 cross compile. We use startswith rather than == to handle this
+    # case.
+    # TODO: There may be other cases where the 64 bit version of the
+    # architecture can run 32 bit binaries (aarch64 and armv7 for example)
+    message('''
+      Cross compiling to different architectures, and the host cannot run
+      the build machine's binaries. Disabling assembly.
+    ''')
+    with_asm = false
+  endif
+endif
+
 with_asm_arch = ''
-if host_machine.cpu_family() == 'x86'
-  if system_has_kms_drm or host_machine.system() == 'gnu'
-    with_asm_arch = 'x86'
-    pre_args += ['-DUSE_X86_ASM', '-DUSE_MMX_ASM', '-DUSE_3DNOW_ASM',
-                 '-DUSE_SSE_ASM']
-
-    if with_glx_read_only_text
-      pre_args += ['-DGLX_X86_READONLY_TEXT']
+if with_asm
+  if host_machine.cpu_family() == 'x86'
+    if system_has_kms_drm or host_machine.system() == 'gnu'
+      with_asm_arch = 'x86'
+      pre_args += ['-DUSE_X86_ASM', '-DUSE_MMX_ASM', '-DUSE_3DNOW_ASM',
+                   '-DUSE_SSE_ASM']
+
+      if with_glx_read_only_text
+         pre_args += ['-DGLX_X86_READONLY_TEXT']
+      endif
+    endif
+  elif host_machine.cpu_family() == 'x86_64'
+    if system_has_kms_drm
+      with_asm_arch = 'x86_64'
+      pre_args += ['-DUSE_X86_64_ASM']
+    endif
+  elif host_machine.cpu_family() == 'arm'
+    if system_has_kms_drm
+      with_asm_arch = 'arm'
+      pre_args += ['-DUSE_ARM_ASM']
+    endif
+  elif host_machine.cpu_family() == 'aarch64'
+    if system_has_kms_drm
+      with_asm_arch = 'aarch64'
+      pre_args += ['-DUSE_AARCH64_ASM']
+    endif
+  elif host_machine.cpu_family() == 'sparc64'
+    if system_has_kms_drm
+      with_asm_arch = 'sparc'
+      pre_args += ['-DUSE_SPARC_ASM']
+    endif
+  elif host_machine.cpu_family().startswith('ppc64') and host_machine.endian() == 'little'
+    if system_has_kms_drm
+      with_asm_arch = 'ppc64le'
+      pre_args += ['-DUSE_PPC64LE_ASM']
     endif
-  endif
-elif host_machine.cpu_family() == 'x86_64'
-  if system_has_kms_drm
-    with_asm_arch = 'x86_64'
-    pre_args += ['-DUSE_X86_64_ASM']
-  endif
-elif host_machine.cpu_family() == 'arm'
-  if system_has_kms_drm
-    with_asm_arch = 'arm'
-    pre_args += ['-DUSE_ARM_ASM']
-  endif
-elif host_machine.cpu_family() == 'aarch64'
-  if system_has_kms_drm
-    with_asm_arch = 'aarch64'
-    pre_args += ['-DUSE_AARCH64_ASM']
-  endif
-elif host_machine.cpu_family() == 'sparc64'
-  if system_has_kms_drm
-    with_asm_arch = 'sparc'
-    pre_args += ['-DUSE_SPARC_ASM']
-  endif
-elif host_machine.cpu_family().startswith('ppc64') and host_machine.endian() == 'little'
-  if system_has_kms_drm
-    with_asm_arch = 'ppc64le'
-    pre_args += ['-DUSE_PPC64LE_ASM']
   endif
 endif
 
diff --git a/meson_options.txt b/meson_options.txt
index b768c15053c..5040284c3bc 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -227,6 +227,12 @@ option(
   value : false,
   description : 'Enable GLVND support.'
 )
+option(
+  'asm',
+  type : 'boolean',
+  value : true,
+  description : 'Build assembly code if possible'
+)
 option(
    'glx-read-only-text',
    type : 'boolean',
diff --git a/src/mesa/Android.libmesa_dricore.mk b/src/mesa/Android.libmesa_dricore.mk
index 8eb6aabe836..792117767b4 100644
--- a/src/mesa/Android.libmesa_dricore.mk
+++ b/src/mesa/Android.libmesa_dricore.mk
@@ -39,9 +39,11 @@ LOCAL_MODULE_CLASS := STATIC_LIBRARIES
 LOCAL_SRC_FILES := \
 	$(MESA_FILES)
 
+ifeq ($(strip $(MESA_ENABLE_ASM)),true)
 ifeq ($(TARGET_ARCH),x86)
 	LOCAL_SRC_FILES += $(X86_FILES)
 endif # x86
+endif # MESA_ENABLE_ASM
 
 ifeq ($(ARCH_X86_HAVE_SSE4_1),true)
 LOCAL_WHOLE_STATIC_LIBRARIES := \
diff --git a/src/mesa/Android.libmesa_st_mesa.mk b/src/mesa/Android.libmesa_st_mesa.mk
index 16153a3c5bd..ddfd03059c5 100644
--- a/src/mesa/Android.libmesa_st_mesa.mk
+++ b/src/mesa/Android.libmesa_st_mesa.mk
@@ -42,9 +42,11 @@ LOCAL_GENERATED_SOURCES := \
 	$(MESA_GEN_GLSL_H) \
 	$(MESA_GEN_NIR_H)
 
+ifeq ($(strip $(MESA_ENABLE_ASM)),true)
 ifeq ($(TARGET_ARCH),x86)
 	LOCAL_SRC_FILES += $(X86_FILES)
 endif # x86
+endif # MESA_ENABLE_ASM
 
 ifeq ($(ARCH_X86_HAVE_SSE4_1),true)
 LOCAL_WHOLE_STATIC_LIBRARIES := \
-- 
2.22.0.709.g102302147b-goog