RISC-V: Add basic support for the Zacas extension

This patch adds support for amocas.{b|h|w|d}. Support for amocas.q
(64/128 bit cas for rv32/64) will be added in a future patch.

Extension: https://github.com/riscv/riscv-zacas
Ratification: https://jira.riscv.org/browse/RVS-680

gcc/ChangeLog:

	* common/config/riscv/riscv-common.cc: Add zacas extension.
	* config/riscv/arch-canonicalize: Make zacas imply zaamo.
	* config/riscv/riscv.opt: Add zacas.
	* config/riscv/sync.md (zacas_atomic_cas_value<mode>): New pattern.
	(atomic_compare_and_swap<mode>): Use new pattern for compare-and-swap ops.
	(zalrsc_atomic_cas_value_strong<mode>): Rename atomic_cas_value_strong.
	* doc/sourcebuild.texi: Add Zacas documentation.

gcc/testsuite/ChangeLog:

	* lib/target-supports.exp: Add zacas testsuite infra support.
	* gcc.target/riscv/amo/zalrsc-rvwmo-compare-exchange-int-acquire-release.c:
	Remove zacas to continue to test the lr/sc pairs.
	* gcc.target/riscv/amo/zalrsc-rvwmo-compare-exchange-int-acquire.c: Ditto.
	* gcc.target/riscv/amo/zalrsc-rvwmo-compare-exchange-int-consume.c: Ditto.
	* gcc.target/riscv/amo/zalrsc-rvwmo-compare-exchange-int-relaxed.c: Ditto.
	* gcc.target/riscv/amo/zalrsc-rvwmo-compare-exchange-int-release.c: Ditto.
	* gcc.target/riscv/amo/zalrsc-rvwmo-compare-exchange-int-seq-cst-relaxed.c: Ditto.
	* gcc.target/riscv/amo/zalrsc-rvwmo-compare-exchange-int-seq-cst.c: Ditto.
	* gcc.target/riscv/amo/zalrsc-ztso-compare-exchange-int-acquire-release.c: Ditto.
	* gcc.target/riscv/amo/zalrsc-ztso-compare-exchange-int-acquire.c: Ditto.
	* gcc.target/riscv/amo/zalrsc-ztso-compare-exchange-int-consume.c: Ditto.
	* gcc.target/riscv/amo/zalrsc-ztso-compare-exchange-int-relaxed.c: Ditto.
	* gcc.target/riscv/amo/zalrsc-ztso-compare-exchange-int-release.c: Ditto.
	* gcc.target/riscv/amo/zalrsc-ztso-compare-exchange-int-seq-cst-relaxed.c: Ditto.
	* gcc.target/riscv/amo/zalrsc-ztso-compare-exchange-int-seq-cst.c: Ditto.
	* gcc.target/riscv/amo/zabha-zacas-preferred-over-zalrsc.c: New test.
	* gcc.target/riscv/amo/zacas-char-requires-zabha.c: New test.
	* gcc.target/riscv/amo/zacas-char-requires-zacas.c: New test.
	* gcc.target/riscv/amo/zacas-preferred-over-zalrsc.c: New test.
	* gcc.target/riscv/amo/zacas-rvwmo-compare-exchange-char-acq-rel.c: New test.
	* gcc.target/riscv/amo/zacas-rvwmo-compare-exchange-char-acquire.c: New test.
	* gcc.target/riscv/amo/zacas-rvwmo-compare-exchange-char-relaxed.c: New test.
	* gcc.target/riscv/amo/zacas-rvwmo-compare-exchange-char-release.c: New test.
	* gcc.target/riscv/amo/zacas-rvwmo-compare-exchange-char-seq-cst.c: New test.
	* gcc.target/riscv/amo/zacas-rvwmo-compare-exchange-compatability-mapping-no-fence.c:
	New test.
	* gcc.target/riscv/amo/zacas-rvwmo-compare-exchange-compatability-mapping.cc: New test.
	* gcc.target/riscv/amo/zacas-rvwmo-compare-exchange-int-acq-rel.c: New test.
	* gcc.target/riscv/amo/zacas-rvwmo-compare-exchange-int-acquire.c: New test.
	* gcc.target/riscv/amo/zacas-rvwmo-compare-exchange-int-relaxed.c: New test.
	* gcc.target/riscv/amo/zacas-rvwmo-compare-exchange-int-release.c: New test.
	* gcc.target/riscv/amo/zacas-rvwmo-compare-exchange-int-seq-cst.c: New test.
	* gcc.target/riscv/amo/zacas-rvwmo-compare-exchange-short-acq-rel.c: New test.
	* gcc.target/riscv/amo/zacas-rvwmo-compare-exchange-short-acquire.c: New test.
	* gcc.target/riscv/amo/zacas-rvwmo-compare-exchange-short-relaxed.c: New test.
	* gcc.target/riscv/amo/zacas-rvwmo-compare-exchange-short-release.c: New test.
	* gcc.target/riscv/amo/zacas-rvwmo-compare-exchange-short-seq-cst.c: New test.
	* gcc.target/riscv/amo/zacas-ztso-compare-exchange-char-seq-cst.c: New test.
	* gcc.target/riscv/amo/zacas-ztso-compare-exchange-char.c: New test.
	* gcc.target/riscv/amo/zacas-ztso-compare-exchange-compatability-mapping-no-fence.c:
	New test.
	* gcc.target/riscv/amo/zacas-ztso-compare-exchange-compatability-mapping.cc: New test.
	* gcc.target/riscv/amo/zacas-ztso-compare-exchange-int-seq-cst.c: New test.
	* gcc.target/riscv/amo/zacas-ztso-compare-exchange-int.c: New test.
	* gcc.target/riscv/amo/zacas-ztso-compare-exchange-short-seq-cst.c: New test.
	* gcc.target/riscv/amo/zacas-ztso-compare-exchange-short.c: New test.

Co-authored-by: Patrick O'Neill <patrick@rivosinc.com>
Tested-by: Andrea Parri <andrea@rivosinc.com>
Signed-Off-By: Gianluca Guida <gianluca@rivosinc.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/gcc/common/config/riscv/riscv-common.cc b/gcc/common/config/riscv/riscv-common.cc
index d291287..0c12e12 100644
--- a/gcc/common/config/riscv/riscv-common.cc
+++ b/gcc/common/config/riscv/riscv-common.cc
@@ -95,6 +95,7 @@ static const riscv_implied_info_t riscv_implied_info[] =
    }},
 
   {"zabha", "zaamo"},
+  {"zacas", "zaamo"},
 
   {"b", "zba"},
   {"b", "zbb"},
@@ -283,6 +284,7 @@ static const struct riscv_ext_version riscv_ext_version_table[] =
   {"zaamo", ISA_SPEC_CLASS_NONE, 1, 0},
   {"zalrsc", ISA_SPEC_CLASS_NONE, 1, 0},
   {"zabha", ISA_SPEC_CLASS_NONE, 1, 0},
+  {"zacas", ISA_SPEC_CLASS_NONE, 1, 0},
 
   {"zba", ISA_SPEC_CLASS_NONE, 1, 0},
   {"zbb", ISA_SPEC_CLASS_NONE, 1, 0},
@@ -1584,6 +1586,7 @@ static const riscv_ext_flag_table_t riscv_ext_flag_table[] =
   {"zaamo",   &gcc_options::x_riscv_za_subext, MASK_ZAAMO},
   {"zalrsc",  &gcc_options::x_riscv_za_subext, MASK_ZALRSC},
   {"zabha",   &gcc_options::x_riscv_za_subext, MASK_ZABHA},
+  {"zacas",   &gcc_options::x_riscv_za_subext, MASK_ZACAS},
 
   {"zba",    &gcc_options::x_riscv_zb_subext, MASK_ZBA},
   {"zbb",    &gcc_options::x_riscv_zb_subext, MASK_ZBB},