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| author | Richard Henderson <rth@twiddle.net> | 2013-06-06 10:46:35 -0700 |
|---|---|---|
| committer | Richard Henderson <rth@twiddle.net> | 2013-07-09 07:15:13 -0700 |
| commit | 1e709f38331ef5bab76cd454c61d4af982cadf0b (patch) | |
| tree | 98b726366322989271ee130d67f96cec235e4fd2 | |
| parent | cb91021a4786efdd6e4ca1ebfd8729481466bbb8 (diff) | |
| download | qemu-1e709f38331ef5bab76cd454c61d4af982cadf0b.zip | |
tcg-arm: Use AT_PLATFORM to detect the host ISA
With this we can generate armv7 insns even when the OS compiles for a
lower common denominator. The macros are arranged so that when we do
compile for a given ISA, all of the runtime checks for that ISA are
optimized away.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
| -rw-r--r-- | tcg/arm/tcg-target.c | 20 |
1 files changed, 16 insertions, 4 deletions
diff --git a/tcg/arm/tcg-target.c b/tcg/arm/tcg-target.c index fde1715d65..4710046a4c 100644 --- a/tcg/arm/tcg-target.c +++ b/tcg/arm/tcg-target.c @@ -41,6 +41,8 @@ # endif #endif +static int arm_arch = __ARM_ARCH; + #if defined(__ARM_ARCH_5T__) \ || defined(__ARM_ARCH_5TE__) || defined(__ARM_ARCH_5TEJ__) # define use_armv5t_instructions 1 @@ -48,8 +50,8 @@ # define use_armv5t_instructions use_armv6_instructions #endif -#define use_armv6_instructions (__ARM_ARCH >= 6) -#define use_armv7_instructions (__ARM_ARCH >= 7) +#define use_armv6_instructions (__ARM_ARCH >= 6 || arm_arch >= 6) +#define use_armv7_instructions (__ARM_ARCH >= 7 || arm_arch >= 7) #ifndef use_idiv_instructions bool use_idiv_instructions; @@ -2028,12 +2030,22 @@ static const TCGTargetOpDef arm_op_defs[] = { static void tcg_target_init(TCGContext *s) { -#if defined(CONFIG_GETAUXVAL) && !defined(use_idiv_instructions) +#if defined(CONFIG_GETAUXVAL) + /* Only probe for the platform and capabilities if we havn't already + determined maximum values at compile time. */ +# if !defined(use_idiv_instructions) { unsigned long hwcap = getauxval(AT_HWCAP); use_idiv_instructions = (hwcap & HWCAP_ARM_IDIVA) != 0; } -#endif +# endif + if (__ARM_ARCH < 7) { + const char *pl = (const char *)getauxval(AT_PLATFORM); + if (pl != NULL && pl[0] == 'v' && pl[1] >= '4' && pl[1] <= '9') { + arm_arch = pl[1] - '0'; + } + } +#endif /* GETAUXVAL */ tcg_regset_set32(tcg_target_available_regs[TCG_TYPE_I32], 0, 0xffff); tcg_regset_set32(tcg_target_call_clobber_regs, 0, |