From 1359af930ee5baf8444b0acc3d55b1e5e1a3879e Mon Sep 17 00:00:00 2001 From: Ben Crocker Date: Thu, 28 Sep 2017 14:09:13 -0400 Subject: [PATCH] gallivm/ppc64le: allow environmental control of Altivec code generation In check_os_altivec_support(), allow control of Altivec (first PPC vector instruction set) code generation via a new environmental control, GALLIVM_ALTIVEC, which is expected to take on a value of 1 or 0. The default is to enable Altivec code generation. This environmental control of Altivec code generation is initially available only #ifdef DEBUG. Cc: "17.2" Signed-off-by: Ben Crocker Acked-by: Roland Scheidegger --- src/gallium/auxiliary/util/u_cpu_detect.c | 32 +++++++++++++++++------ 1 file changed, 24 insertions(+), 8 deletions(-) diff --git a/src/gallium/auxiliary/util/u_cpu_detect.c b/src/gallium/auxiliary/util/u_cpu_detect.c index 4e71041bc9a..6a59f271a83 100644 --- a/src/gallium/auxiliary/util/u_cpu_detect.c +++ b/src/gallium/auxiliary/util/u_cpu_detect.c @@ -132,16 +132,32 @@ check_os_altivec_support(void) if (setjmp(__lv_powerpc_jmpbuf)) { signal(SIGILL, SIG_DFL); } else { - __lv_powerpc_canjump = 1; + boolean enable_altivec = TRUE; /* Default: enable if available, and if not overridden */ +#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. + * lp_build_create_jit_compiler_for_module(). + * If you want to disable Altivec code generation, the best place to do it is here. + */ + char *env_control = getenv("GALLIVM_ALTIVEC"); /* 1=enable (default); 0=disable */ + if (env_control && env_control[0] == '0') { + enable_altivec = FALSE; + } +#endif + if (enable_altivec) { + __lv_powerpc_canjump = 1; - __asm __volatile - ("mtspr 256, %0\n\t" - "vand %%v0, %%v0, %%v0" - : - : "r" (-1)); + __asm __volatile + ("mtspr 256, %0\n\t" + "vand %%v0, %%v0, %%v0" + : + : "r" (-1)); - signal(SIGILL, SIG_DFL); - util_cpu_caps.has_altivec = 1; + signal(SIGILL, SIG_DFL); + util_cpu_caps.has_altivec = 1; + } else { + util_cpu_caps.has_altivec = 0; + } } #endif /* !PIPE_OS_APPLE */ } -- 2.30.2