Message ID | 1356733022-4341-1-git-send-email-rth@twiddle.net |
---|---|
State | New |
Headers | show |
Thanks, applied. On Fri, Dec 28, 2012 at 10:17 PM, Richard Henderson <rth@twiddle.net> wrote: > Existing compile-time detection is spotty at best. Convert > it all to runtime detection instead. > > Signed-off-by: Richard Henderson <rth@twiddle.net> > --- > configure | 19 +++++++++++++++++++ > tcg/i386/tcg-target.c | 31 ++++++++++++++++++++++++++++++- > tcg/i386/tcg-target.h | 5 ----- > 3 files changed, 49 insertions(+), 6 deletions(-) > > diff --git a/configure b/configure > index 99c1ec3..b0c7e54 100755 > --- a/configure > +++ b/configure > @@ -3086,6 +3086,21 @@ if compile_prog "" "" ; then > has_environ=yes > fi > > +######################################## > +# check if cpuid.h is usable. > + > +cpuid_h=no > +cat > $TMPC << EOF > +#include <cpuid.h> > +int main(void) { > + return 0; > +} > +EOF > +if compile_prog "" "" ; then > + cpuid_h=yes > +fi > + > + > ########################################## > # End of CC checks > # After here, no more $cc or $ld runs > @@ -3611,6 +3626,10 @@ if test "$has_environ" = "yes" ; then > echo "CONFIG_HAS_ENVIRON=y" >> $config_host_mak > fi > > +if test "$cpuid_h" = "yes" ; then > + echo "CONFIG_CPUID_H=y" >> $config_host_mak > +fi > + > if test "$glusterfs" = "yes" ; then > echo "CONFIG_GLUSTERFS=y" >> $config_host_mak > fi > diff --git a/tcg/i386/tcg-target.c b/tcg/i386/tcg-target.c > index ae82746..e083874 100644 > --- a/tcg/i386/tcg-target.c > +++ b/tcg/i386/tcg-target.c > @@ -97,6 +97,18 @@ static const int tcg_target_call_oarg_regs[] = { > # define TCG_REG_L1 TCG_REG_EDX > #endif > > +/* For 32-bit, we are going to attempt to determine at runtime whether cmov > + is available. However, the host compiler must supply <cpuid.h>, as we're > + not going to go so far as our own inline assembly. */ > +#if TCG_TARGET_REG_BITS == 64 > +# define have_cmov 1 > +#elif defined(CONFIG_CPUID_H) > +#include <cpuid.h> > +static bool have_cmov; > +#else > +# define have_cmov 0 > +#endif > + > static uint8_t *tb_ret_addr; > > static void patch_reloc(uint8_t *code_ptr, int type, > @@ -943,7 +955,14 @@ static void tcg_out_movcond32(TCGContext *s, TCGCond cond, TCGArg dest, > TCGArg v1) > { > tcg_out_cmp(s, c1, c2, const_c2, 0); > - tcg_out_modrm(s, OPC_CMOVCC | tcg_cond_to_jcc[cond], dest, v1); > + if (have_cmov) { > + tcg_out_modrm(s, OPC_CMOVCC | tcg_cond_to_jcc[cond], dest, v1); > + } else { > + int over = gen_new_label(); > + tcg_out_jxx(s, tcg_cond_to_jcc[tcg_invert_cond(cond)], over, 1); > + tcg_out_mov(s, TCG_TYPE_I32, dest, v1); > + tcg_out_label(s, over, s->code_ptr); > + } > } > > #if TCG_TARGET_REG_BITS == 64 > @@ -2243,6 +2262,16 @@ static void tcg_target_qemu_prologue(TCGContext *s) > > static void tcg_target_init(TCGContext *s) > { > + /* For 32-bit, 99% certainty that we're running on hardware that supports > + cmov, but we still need to check. In case cmov is not available, we'll > + use a small forward branch. */ > +#ifndef have_cmov > + { > + unsigned a, b, c, d; > + have_cmov = (__get_cpuid(1, &a, &b, &c, &d) && (d & bit_CMOV)); > + } > +#endif > + > #if !defined(CONFIG_USER_ONLY) > /* fail safe */ > if ((1 << CPU_TLB_ENTRY_BITS) != sizeof(CPUTLBEntry)) > diff --git a/tcg/i386/tcg-target.h b/tcg/i386/tcg-target.h > index 5352ac0..e63db9c 100644 > --- a/tcg/i386/tcg-target.h > +++ b/tcg/i386/tcg-target.h > @@ -91,12 +91,7 @@ typedef enum { > #define TCG_TARGET_HAS_nand_i32 0 > #define TCG_TARGET_HAS_nor_i32 0 > #define TCG_TARGET_HAS_deposit_i32 1 > -#if defined(__x86_64__) || defined(__i686__) > -/* Use cmov only if the compiler is already doing so. */ > #define TCG_TARGET_HAS_movcond_i32 1 > -#else > -#define TCG_TARGET_HAS_movcond_i32 0 > -#endif > > #if TCG_TARGET_REG_BITS == 64 > #define TCG_TARGET_HAS_div2_i64 1 > -- > 1.7.11.7 >
diff --git a/configure b/configure index 99c1ec3..b0c7e54 100755 --- a/configure +++ b/configure @@ -3086,6 +3086,21 @@ if compile_prog "" "" ; then has_environ=yes fi +######################################## +# check if cpuid.h is usable. + +cpuid_h=no +cat > $TMPC << EOF +#include <cpuid.h> +int main(void) { + return 0; +} +EOF +if compile_prog "" "" ; then + cpuid_h=yes +fi + + ########################################## # End of CC checks # After here, no more $cc or $ld runs @@ -3611,6 +3626,10 @@ if test "$has_environ" = "yes" ; then echo "CONFIG_HAS_ENVIRON=y" >> $config_host_mak fi +if test "$cpuid_h" = "yes" ; then + echo "CONFIG_CPUID_H=y" >> $config_host_mak +fi + if test "$glusterfs" = "yes" ; then echo "CONFIG_GLUSTERFS=y" >> $config_host_mak fi diff --git a/tcg/i386/tcg-target.c b/tcg/i386/tcg-target.c index ae82746..e083874 100644 --- a/tcg/i386/tcg-target.c +++ b/tcg/i386/tcg-target.c @@ -97,6 +97,18 @@ static const int tcg_target_call_oarg_regs[] = { # define TCG_REG_L1 TCG_REG_EDX #endif +/* For 32-bit, we are going to attempt to determine at runtime whether cmov + is available. However, the host compiler must supply <cpuid.h>, as we're + not going to go so far as our own inline assembly. */ +#if TCG_TARGET_REG_BITS == 64 +# define have_cmov 1 +#elif defined(CONFIG_CPUID_H) +#include <cpuid.h> +static bool have_cmov; +#else +# define have_cmov 0 +#endif + static uint8_t *tb_ret_addr; static void patch_reloc(uint8_t *code_ptr, int type, @@ -943,7 +955,14 @@ static void tcg_out_movcond32(TCGContext *s, TCGCond cond, TCGArg dest, TCGArg v1) { tcg_out_cmp(s, c1, c2, const_c2, 0); - tcg_out_modrm(s, OPC_CMOVCC | tcg_cond_to_jcc[cond], dest, v1); + if (have_cmov) { + tcg_out_modrm(s, OPC_CMOVCC | tcg_cond_to_jcc[cond], dest, v1); + } else { + int over = gen_new_label(); + tcg_out_jxx(s, tcg_cond_to_jcc[tcg_invert_cond(cond)], over, 1); + tcg_out_mov(s, TCG_TYPE_I32, dest, v1); + tcg_out_label(s, over, s->code_ptr); + } } #if TCG_TARGET_REG_BITS == 64 @@ -2243,6 +2262,16 @@ static void tcg_target_qemu_prologue(TCGContext *s) static void tcg_target_init(TCGContext *s) { + /* For 32-bit, 99% certainty that we're running on hardware that supports + cmov, but we still need to check. In case cmov is not available, we'll + use a small forward branch. */ +#ifndef have_cmov + { + unsigned a, b, c, d; + have_cmov = (__get_cpuid(1, &a, &b, &c, &d) && (d & bit_CMOV)); + } +#endif + #if !defined(CONFIG_USER_ONLY) /* fail safe */ if ((1 << CPU_TLB_ENTRY_BITS) != sizeof(CPUTLBEntry)) diff --git a/tcg/i386/tcg-target.h b/tcg/i386/tcg-target.h index 5352ac0..e63db9c 100644 --- a/tcg/i386/tcg-target.h +++ b/tcg/i386/tcg-target.h @@ -91,12 +91,7 @@ typedef enum { #define TCG_TARGET_HAS_nand_i32 0 #define TCG_TARGET_HAS_nor_i32 0 #define TCG_TARGET_HAS_deposit_i32 1 -#if defined(__x86_64__) || defined(__i686__) -/* Use cmov only if the compiler is already doing so. */ #define TCG_TARGET_HAS_movcond_i32 1 -#else -#define TCG_TARGET_HAS_movcond_i32 0 -#endif #if TCG_TARGET_REG_BITS == 64 #define TCG_TARGET_HAS_div2_i64 1
Existing compile-time detection is spotty at best. Convert it all to runtime detection instead. Signed-off-by: Richard Henderson <rth@twiddle.net> --- configure | 19 +++++++++++++++++++ tcg/i386/tcg-target.c | 31 ++++++++++++++++++++++++++++++- tcg/i386/tcg-target.h | 5 ----- 3 files changed, 49 insertions(+), 6 deletions(-)