https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71233
--- Comment #43 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-8 branch has been updated by Kyrylo Tkachov <ktkac...@gcc.gnu.org>: https://gcc.gnu.org/g:26020c849802a03f7a0634636d752ffbc7729096 commit r8-10535-g26020c849802a03f7a0634636d752ffbc7729096 Author: Kyrylo Tkachov <kyrylo.tkac...@arm.com> Date: Mon Oct 21 10:52:05 2019 +0000 AArch64: Implement __rndr, __rndrrs intrinsics This patch implements the recently published[1] __rndr and __rndrrs intrinsics used to access the RNG in Armv8.5-A. The __rndrrs intrinsics can be used to reseed the generator too. They are guarded by the __ARM_FEATURE_RNG feature macro. A quirk with these intrinsics is that they store the random number in their pointer argument and return a status code if the generation succeeded. The instructions themselves write the CC flags indicating the success of the operation that we can then read with a CSET. Therefore this implementation makes use of the IGNORE indicator to the builtin expand machinery to avoid generating the CSET if its result is unused (the CC reg clobbering effect is still reflected in the pattern). I've checked that using unspec_volatile prevents undesirable CSEing of the instructions. [1] https://developer.arm.com/docs/101028/latest/data-processing-intrinsics gcc/ PR target/71233 * config/aarch64/aarch64.md (UNSPEC_RNDR, UNSPEC_RNDRRS): Define. (aarch64_rndr): New define_insn. (aarch64_rndrrs): Likewise. * config/aarch64/aarch64.h (AARCH64_ISA_RNG): Define. (TARGET_RNG): Likewise. (AARCH64_FL_RNG): Likewise. * config/aarch64/aarch64-option-extensions.def (rng): Define. * config/aarch64/aarch64-builtins.c (enum aarch64_builtins): Add AARCH64_BUILTIN_RNG_RNDR, AARCH64_BUILTIN_RNG_RNDRRS. (aarch64_init_rng_builtins): Define. (aarch64_init_builtins): Call aarch64_init_rng_builtins. (aarch64_expand_rng_builtin): Define. (aarch64_expand_builtin): Use IGNORE argument, handle RNG builtins. * config/aarch64/aarch64-c.c (aarch64_update_cpp_builtins): Define __ARM_FEATURE_RNG when TARGET_RNG. * config/aarch64/arm_acle.h (__rndr, __rndrrs): Define. gcc/testsuite/ PR target/71233 * gcc.target/aarch64/acle/rng_1.c: New test.
