Add support for POWER8/VSX

Add ppc, ppc64 and ppc64le on all_platforms and ARCH_LIST

Add VSX flags and check for -mvsx

Define empty setup_rtcd_internal

Add Altivec detection based on:
http://freevec.org/function/altivec_runtime_detection_linux

Detect VSX at runtime when enabled

Change-Id: I304f4d8c5fee0ff19b6483cd2e9cc50d6ddec472
Signed-off-by: Rafael de Lucena Valle <rafaeldelucena@gmail.com>

build/make/Makefile

@@ -124,6 +124,7 @@ ifeq ($(TOOLCHAIN), x86-os2-gcc)
 CFLAGS += -mstackrealign
 endif
 
+# x86[_64]
 $(BUILD_PFX)%_mmx.c.d: CFLAGS += -mmmx
 $(BUILD_PFX)%_mmx.c.o: CFLAGS += -mmmx
 $(BUILD_PFX)%_sse2.c.d: CFLAGS += -msse2
@@ -139,6 +140,10 @@ $(BUILD_PFX)%_avx.c.o: CFLAGS += -mavx
 $(BUILD_PFX)%_avx2.c.d: CFLAGS += -mavx2
 $(BUILD_PFX)%_avx2.c.o: CFLAGS += -mavx2
 
+# POWER
+$(BUILD_PFX)%_vsx.c.d: CFLAGS += -mvsx
+$(BUILD_PFX)%_vsx.c.o: CFLAGS += -mvsx
+
 $(BUILD_PFX)%.c.d: %.c
 	$(if $(quiet),@echo "    [DEP] $@")
 	$(qexec)mkdir -p $(dir $@)

build/make/configure.sh

@@ -697,6 +697,9 @@ process_common_toolchain() {
       *sparc*)
         tgt_isa=sparc
         ;;
+      power*)
+        tgt_isa=ppc
+        ;;
     esac
 
     # detect tgt_os
@@ -782,6 +785,9 @@ process_common_toolchain() {
     mips*)
       enable_feature mips
       ;;
+    ppc*)
+      enable_feature ppc
+      ;;
   esac
 
   # PIC is probably what we want when building shared libs
@@ -1159,6 +1165,11 @@ EOF
       check_add_asflags -march=${tgt_isa}
       check_add_asflags -KPIC
       ;;
+    ppc*)
+      link_with_cc=gcc
+      setup_gnu_toolchain
+      check_gcc_machine_option "vsx"
+      ;;
     x86*)
       case  ${tgt_os} in
         win*)

build/make/rtcd.pl

@@ -335,6 +335,36 @@ EOF
   common_bottom;
 }
 
+sub ppc() {
+  determine_indirection("c", @ALL_ARCHS);
+
+  # Assign the helper variable for each enabled extension
+  foreach my $opt (@ALL_ARCHS) {
+    my $opt_uc = uc $opt;
+    eval "\$have_${opt}=\"flags & HAS_${opt_uc}\"";
+  }
+
+  common_top;
+  print <<EOF;
+#include "vpx_config.h"
+
+#ifdef RTCD_C
+#include "vpx_ports/ppc.h"
+static void setup_rtcd_internal(void)
+{
+    int flags = ppc_simd_caps();
+    (void)flags;
+EOF
+
+  set_function_pointers("c", @ALL_ARCHS);
+
+  print <<EOF;
+}
+#endif
+EOF
+  common_bottom;
+}
+
 sub unoptimized() {
   determine_indirection "c";
   common_top;
@@ -390,6 +420,9 @@ if ($opts{arch} eq 'x86') {
 } elsif ($opts{arch} eq 'armv8' || $opts{arch} eq 'arm64' ) {
   @ALL_ARCHS = filter(qw/neon/);
   arm;
+} elsif ($opts{arch} eq 'ppc' ) {
+  @ALL_ARCHS = filter(qw/vsx/);
+  ppc;
 } else {
   unoptimized;
 }

configure

@@ -113,6 +113,9 @@ all_platforms="${all_platforms} armv7s-darwin-gcc"
 all_platforms="${all_platforms} armv8-linux-gcc"
 all_platforms="${all_platforms} mips32-linux-gcc"
 all_platforms="${all_platforms} mips64-linux-gcc"
+all_platforms="${all_platforms} ppc-linux-gcc"
+all_platforms="${all_platforms} ppc64-linux-gcc"
+all_platforms="${all_platforms} ppc64le-linux-gcc"
 all_platforms="${all_platforms} sparc-solaris-gcc"
 all_platforms="${all_platforms} x86-android-gcc"
 all_platforms="${all_platforms} x86-darwin8-gcc"
@@ -225,6 +228,7 @@ ARCH_LIST="
     mips
     x86
     x86_64
+    ppc
 "
 ARCH_EXT_LIST_X86="
     mmx
@@ -246,6 +250,8 @@ ARCH_EXT_LIST="
     mips64
 
     ${ARCH_EXT_LIST_X86}
+
+    vsx
 "
 HAVE_LIST="
     ${ARCH_EXT_LIST}

vp8/common/generic/systemdependent.c

@@ -94,5 +94,7 @@ void vp8_machine_specific_config(VP8_COMMON *ctx) {
   ctx->cpu_caps = arm_cpu_caps();
 #elif ARCH_X86 || ARCH_X86_64
   ctx->cpu_caps = x86_simd_caps();
+#elif ARCH_PPC
+  ctx->cpu_caps = ppc_simd_caps();
 #endif
 }

vpx_ports/ppc.h

@@ -0,0 +1,29 @@
+/*
+ *  Copyright (c) 2017 The WebM project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef VPX_PORTS_PPC_H_
+#define VPX_PORTS_PPC_H_
+#include <stdlib.h>
+
+#include "./vpx_config.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define HAS_VSX 0x01
+
+int ppc_simd_caps(void);
+
+#ifdef __cplusplus
+}  // extern "C"
+#endif
+
+#endif  // VPX_PORTS_PPC_H_

vpx_ports/ppc_cpudetect.c

@@ -0,0 +1,80 @@
+/*
+ *  Copyright (c) 2017 The WebM project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdint.h>
+#include <asm/cputable.h>
+#include <linux/auxvec.h>
+
+#include "./vpx_config.h"
+#include "vpx_ports/ppc.h"
+
+#if CONFIG_RUNTIME_CPU_DETECT
+static int cpu_env_flags(int *flags) {
+  char *env;
+  env = getenv("VPX_SIMD_CAPS");
+  if (env && *env) {
+    *flags = (int)strtol(env, NULL, 0);
+    return 0;
+  }
+  *flags = 0;
+  return -1;
+}
+
+static int cpu_env_mask(void) {
+  char *env;
+  env = getenv("VPX_SIMD_CAPS_MASK");
+  return env && *env ? (int)strtol(env, NULL, 0) : ~0;
+}
+
+int ppc_simd_caps(void) {
+  int flags;
+  int mask;
+  int fd;
+  ssize_t count;
+  unsigned int i;
+  uint64_t buf[64];
+
+  // If VPX_SIMD_CAPS is set then allow only those capabilities.
+  if (!cpu_env_flags(&flags)) {
+    return flags;
+  }
+
+  mask = cpu_env_mask();
+
+  fd = open("/proc/self/auxv", O_RDONLY);
+  if (fd < 0) {
+    return 0;
+  }
+
+  while ((count = read(fd, buf, sizeof(buf))) > 0) {
+    for (i = 0; i < (count / sizeof(*buf)); i += 2) {
+      if (buf[i] == AT_HWCAP) {
+#if HAVE_VSX
+        if (buf[i + 1] & PPC_FEATURE_HAS_VSX) {
+          flags |= HAS_VSX;
+        }
+#endif  // HAVE_VSX
+        goto out_close;
+      } else if (buf[i] == AT_NULL) {
+        goto out_close;
+      }
+    }
+  }
+out_close:
+  close(fd);
+  return flags & mask;
+}
+#else
+// If there is no RTCD the function pointers are not used and can not be
+// changed.
+int ppc_simd_caps(void) { return 0; }
+#endif  // CONFIG_RUNTIME_CPU_DETECT

vpx_ports/vpx_ports.mk

@@ -25,3 +25,6 @@ endif
 
 PORTS_SRCS-$(ARCH_ARM) += arm_cpudetect.c
 PORTS_SRCS-$(ARCH_ARM) += arm.h
+
+PORTS_SRCS-$(ARCH_PPC) += ppc_cpudetect.c
+PORTS_SRCS-$(ARCH_PPC) += ppc.h