x86: add a misc utility header

1 files changed, 40 insertions, 0 deletions

diff --git a/util.asm b/util.asm
new file mode 100644
index 0000000..846ea3b
--- /dev/null
+++ b/util.asm
@@ -0,0 +1,40 @@
+;
+; Various ASM utility macros
+; Copyright 2019 Anton Khirnov <anton@khirnov.net>
+;
+; This program is free software: you can redistribute it and/or modify
+; it under the terms of the GNU General Public License as published by
+; the Free Software Foundation, either version 3 of the License, or
+; (at your option) any later version.
+;
+; This program is distributed in the hope that it will be useful,
+; but WITHOUT ANY WARRANTY; without even the implied warranty of
+; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+; GNU General Public License for more details.
+;
+; You should have received a copy of the GNU General Public License
+; along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+%define _IMM8SPLAT2B(x) (((x) << 6) | ((x) << 4) | ((x) << 2) | (x))
+%define _IMM4SPLAT1B(x) (((x) << 3) | ((x) << 2) | ((x) << 1) | (x))
+
+; splat packed double - copy the specified double into all positions in the
+; destination
+
+; %1 destination register
+; %2 source register (may be same as dst)
+; %3 index of the element in the source to splat
+%macro SPLATPD 3
+    %if %3 > 3
+        %error Invalid selector %3
+    %endif
+
+    %if mmsize == 32 && cpuflag(avx2)
+        vpermpd %1, %2, _IMM8SPLAT2B(%3)
+    %elif mmsize == 32 && cpuflag(avx)
+        shufpd %1, %2, %2, _IMM4SPLAT1B(%3 & 1)
+        vperm2f128 %1, %1, ((%3 & 2) >> 1) * 0x11
+    %else
+        %error %? not supported with cpuname
+    %endif
+%endmacro