meson: allow configuring the x86-64 baseline
Add a Meson option to configure which x86-64 instruction
set to use. QEMU will now default to x86-64-v1 + cmpxchg16b for
64-bit builds (that corresponds to a Pentium 4 for 32-bit builds).
The baseline can be tuned down to Pentium Pro for 32-bit builds (with
-Dx86_version=0), or up as desired.
Acked-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/meson.build b/meson.build
index 97e00d6..6e694ec 100644
--- a/meson.build
+++ b/meson.build
@@ -336,15 +336,40 @@
qemu_common_flags = ['-march=i486'] + qemu_common_flags
endif
-# Assume x86-64-v2 (minus CMPXCHG16B for 32-bit code)
-if host_arch == 'i386'
- qemu_common_flags = ['-mfpmath=sse'] + qemu_common_flags
-endif
+# Pick x86-64 baseline version
if host_arch in ['i386', 'x86_64']
- qemu_common_flags = ['-mpopcnt', '-msse4.2'] + qemu_common_flags
-endif
-if host_arch == 'x86_64'
- qemu_common_flags = ['-mcx16'] + qemu_common_flags
+ if get_option('x86_version') == '0' and host_arch == 'x86_64'
+ error('x86_64-v1 required for x86-64 hosts')
+ endif
+
+ # add flags for individual instruction set extensions
+ if get_option('x86_version') >= '1'
+ if host_arch == 'i386'
+ qemu_common_flags = ['-mfpmath=sse'] + qemu_common_flags
+ else
+ # present on basically all processors but technically not part of
+ # x86-64-v1, so only include -mneeded for x86-64 version 2 and above
+ qemu_common_flags = ['-mcx16'] + qemu_common_flags
+ endif
+ endif
+ if get_option('x86_version') >= '2'
+ qemu_common_flags = ['-mpopcnt'] + qemu_common_flags
+ qemu_common_flags = cc.get_supported_arguments('-mneeded') + qemu_common_flags
+ endif
+ if get_option('x86_version') >= '3'
+ qemu_common_flags = ['-mmovbe', '-mabm', '-mbmi1', '-mbmi2', '-mfma', '-mf16c'] + qemu_common_flags
+ endif
+
+ # add required vector instruction set (each level implies those below)
+ if get_option('x86_version') == '1'
+ qemu_common_flags = ['-msse2'] + qemu_common_flags
+ elif get_option('x86_version') == '2'
+ qemu_common_flags = ['-msse4.2'] + qemu_common_flags
+ elif get_option('x86_version') == '3'
+ qemu_common_flags = ['-mavx2'] + qemu_common_flags
+ elif get_option('x86_version') == '4'
+ qemu_common_flags = ['-mavx512f', '-mavx512bw', '-mavx512cd', '-mavx512dq', '-mavx512vl'] + qemu_common_flags
+ endif
endif
if get_option('prefer_static')
