Previously gallivm would attempt to use VSX instructions on all systems
where it detected that Altivec is supported; however, VSX was added to
POWER long after Altivec, causing lots of crashes on older POWER/PPC
hardware, e.g. PPC Macs. By detecting VSX separately from Altivec we can
automatically disable it on hardware that supports Altivec but not VSX
Signed-off-by: Vicki Pfau <v...@endrift.com>
---
src/gallium/auxiliary/gallivm/lp_bld_misc.cpp | 21 +++----------------
src/gallium/auxiliary/util/u_cpu_detect.c | 14 ++++++++++++-
src/gallium/auxiliary/util/u_cpu_detect.h | 1 +
3 files changed, 17 insertions(+), 19 deletions(-)
diff --git a/src/gallium/auxiliary/gallivm/lp_bld_misc.cpp
b/src/gallium/auxiliary/gallivm/lp_bld_misc.cpp
index 79dbedbb56..fcbdd5050f 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_misc.cpp
+++ b/src/gallium/auxiliary/gallivm/lp_bld_misc.cpp
@@ -650,26 +650,11 @@
lp_build_create_jit_compiler_for_module(LLVMExecutionEngineRef *OutJIT,
* which are fixed in LLVM 4.0.
*
* With LLVM 4.0 or higher:
- * Make sure VSX instructions are ENABLED, unless
- * a) the entire -mattr option is overridden via GALLIVM_MATTRS, or
- * b) VSX instructions are explicitly enabled/disabled via
GALLIVM_VSX=1 or 0.
+ * Make sure VSX instructions are ENABLED (if supported), unless
+ * VSX instructions are explicitly enabled/disabled via
GALLIVM_VSX=1 or 0.
*/
if (util_cpu_caps.has_altivec) {
- char *env_mattrs = getenv("GALLIVM_MATTRS");
- if (env_mattrs) {
- MAttrs.push_back(env_mattrs);
- }
- else {
- boolean enable_vsx = true;
- char *env_vsx = getenv("GALLIVM_VSX");
- if (env_vsx && env_vsx[0] == '0') {
- enable_vsx = false;
- }
- if (enable_vsx)
- MAttrs.push_back("+vsx");
- else
- MAttrs.push_back("-vsx");
- }
+ MAttrs.push_back(util_cpu_caps.has_vsx ? "+vsx" : "-vsx");
}
#endif
#endif
diff --git a/src/gallium/auxiliary/util/u_cpu_detect.c
b/src/gallium/auxiliary/util/u_cpu_detect.c
index 3c6ae4ea1a..14003aa769 100644
--- a/src/gallium/auxiliary/util/u_cpu_detect.c
+++ b/src/gallium/auxiliary/util/u_cpu_detect.c
@@ -133,6 +133,7 @@ check_os_altivec_support(void)
signal(SIGILL, SIG_DFL);
} else {
boolean enable_altivec = TRUE; /* Default: enable if
available, and if not overridden */
+ boolean enable_vsx = TRUE;
#ifdef DEBUG
/* Disabling Altivec code generation is not the same as
disabling VSX code generation,
* which can be done simply by passing -mattr=-vsx to the
LLVM compiler; cf.
@@ -144,6 +145,11 @@ check_os_altivec_support(void)
enable_altivec = FALSE;
}
#endif
+ /* VSX instructions can be explicitly enabled/disabled via
GALLIVM_VSX=1 or 0 */
+ char *env_vsx = getenv("GALLIVM_VSX");
+ if (env_vsx && env_vsx[0] == '0') {
+ enable_vsx = FALSE;
+ }
if (enable_altivec) {
__lv_powerpc_canjump = 1;
@@ -153,8 +159,13 @@ check_os_altivec_support(void)
:
: "r" (-1));
- signal(SIGILL, SIG_DFL);
util_cpu_caps.has_altivec = 1;
+
+ if (enable_vsx) {
+ __asm __volatile("xxland %vs0, %vs0, %vs0");
+ util_cpu_caps.has_vsx = 1;
+ }
+ signal(SIGILL, SIG_DFL);
} else {
util_cpu_caps.has_altivec = 0;
}
@@ -536,6 +547,7 @@ util_cpu_detect(void)
debug_printf("util_cpu_caps.has_3dnow_ext = %u\n",
util_cpu_caps.has_3dnow_ext);
debug_printf("util_cpu_caps.has_xop = %u\n",
util_cpu_caps.has_xop);
debug_printf("util_cpu_caps.has_altivec = %u\n",
util_cpu_caps.has_altivec);
+ debug_printf("util_cpu_caps.has_vsx = %u\n",
util_cpu_caps.has_vsx);
debug_printf("util_cpu_caps.has_neon = %u\n",
util_cpu_caps.has_neon);
debug_printf("util_cpu_caps.has_daz = %u\n",
util_cpu_caps.has_daz);
debug_printf("util_cpu_caps.has_avx512f = %u\n",
util_cpu_caps.has_avx512f);
diff --git a/src/gallium/auxiliary/util/u_cpu_detect.h
b/src/gallium/auxiliary/util/u_cpu_detect.h
index 7a63d55028..19f5567ca7 100644
--- a/src/gallium/auxiliary/util/u_cpu_detect.h
+++ b/src/gallium/auxiliary/util/u_cpu_detect.h
@@ -71,6 +71,7 @@ struct util_cpu_caps {
unsigned has_3dnow_ext:1;
unsigned has_xop:1;
unsigned has_altivec:1;
+ unsigned has_vsx:1;
unsigned has_daz:1;
unsigned has_neon:1;
