[RISCV][MC] MC layer support for the experimental zalasr extension (#79911)

This PR implements experimental support for the RISC-V Atomic
Load-Acquire and Store-Release Extension (Zalasr). It has been approved
to be pursued as a fast track extension
(https://lists.riscv.org/g/tech-unprivileged/topic/arc_architecture_review/101951698),
but has not yet been approved by ARC or ratified. See
https://github.com/mehnadnerd/riscv-zalasr for draft spec.

---------

Co-authored-by: brs <turtwig@utexas.edu>
Co-authored-by: Philip Reames <preames@rivosinc.com>

5 files changed, 180 insertions, 0 deletions

diff --git a/llvm/test/MC/RISCV/attribute-arch.s b/llvm/test/MC/RISCV/attribute-arch.s
index 5f9a7ca..8810ca67 100644
--- a/llvm/test/MC/RISCV/attribute-arch.s
+++ b/llvm/test/MC/RISCV/attribute-arch.s
@@ -309,6 +309,9 @@
 .attribute arch, "rv32izacas1p0"
 # CHECK: attribute      5, "rv32i2p1_a2p1_zacas1p0"
 
+.attribute arch, "rv32izalasr0p1"
+# CHECK: attribute      5, "rv32i2p1_zalasr0p1"
+
 .attribute arch, "rv32i_xcvalu"
 # CHECK: attribute      5, "rv32i2p1_xcvalu1p0"
 
diff --git a/llvm/test/MC/RISCV/rv32zalasr-invalid.s b/llvm/test/MC/RISCV/rv32zalasr-invalid.s
new file mode 100644
index 0000000..3731c85
--- /dev/null
+++ b/llvm/test/MC/RISCV/rv32zalasr-invalid.s
@@ -0,0 +1,40 @@
+# RUN: not llvm-mc -triple riscv32 -mattr=+experimental-zalasr < %s 2>&1 | FileCheck -check-prefixes=CHECK %s
+
+# CHECK: error: instruction requires the following: RV64I Base Instruction Set{{$}}
+ld.aq a1, (t0)
+
+# CHECK: error: instruction requires the following: RV64I Base Instruction Set{{$}}
+ld.aqrl a1, (t0)
+
+# CHECK: error: instruction requires the following: RV64I Base Instruction Set{{$}}
+sd.rl a1, (t0)
+
+# CHECK: error: instruction requires the following: RV64I Base Instruction Set{{$}}
+sd.aqrl a1, (t0)
+
+# CHECK: error: unrecognized instruction mnemonic
+lw. a1, (t0)
+
+# CHECK: error: unrecognized instruction mnemonic
+lw.rl t3, 0(t5)
+
+# CHECK: error: unrecognized instruction mnemonic
+lh.rlaq t4, (t6)
+
+# CHECK: error: unrecognized instruction mnemonic
+sb. a1, (t0)
+
+# CHECK: error: unrecognized instruction mnemonic
+sh.aq t3, 0(t5)
+
+# CHECK: error: unrecognized instruction mnemonic
+sh.rlaq t4, (t6)
+
+# CHECK: error: optional integer offset must be 0
+lw.aq zero, 1(a0)
+
+# CHECK: error: optional integer offset must be 0
+sw.rl t1, 2(s0)
+
+# CHECK: error: optional integer offset must be 0
+sb.aqrl sp, 3(s2)
diff --git a/llvm/test/MC/RISCV/rv32zalasr-valid.s b/llvm/test/MC/RISCV/rv32zalasr-valid.s
new file mode 100644
index 0000000..7b2668b
--- /dev/null
+++ b/llvm/test/MC/RISCV/rv32zalasr-valid.s
@@ -0,0 +1,78 @@
+# RUN: llvm-mc %s -triple=riscv32 -mattr=+experimental-zalasr -riscv-no-aliases -show-encoding \
+# RUN:     | FileCheck -check-prefixes=CHECK-ASM,CHECK-ASM-AND-OBJ %s
+# RUN: llvm-mc -filetype=obj -triple=riscv32 -mattr=+experimental-zalasr < %s \
+# RUN:     | llvm-objdump --mattr=+experimental-zalasr -M no-aliases -d -r - \
+# RUN:     | FileCheck --check-prefix=CHECK-ASM-AND-OBJ %s
+# RUN: llvm-mc %s -triple=riscv64 -mattr=+experimental-zalasr -riscv-no-aliases -show-encoding \
+# RUN:     | FileCheck -check-prefixes=CHECK-ASM,CHECK-ASM-AND-OBJ %s
+# RUN: llvm-mc -filetype=obj -triple=riscv64 -mattr=+experimental-zalasr < %s \
+# RUN:     | llvm-objdump --mattr=+experimental-zalasr -M no-aliases -d -r - \
+# RUN:     | FileCheck --check-prefix=CHECK-ASM-AND-OBJ %s
+#
+# RUN: not llvm-mc -triple riscv32 \
+# RUN:     -riscv-no-aliases -show-encoding < %s 2>&1 \
+# RUN:     | FileCheck --check-prefixes=CHECK-NO-EXT %s
+# RUN: not llvm-mc -triple riscv64 \
+# RUN:     -riscv-no-aliases -show-encoding < %s 2>&1 \
+# RUN:     | FileCheck --check-prefixes=CHECK-NO-EXT %s
+
+# CHECK-ASM-AND-OBJ: lb.aq t1, (a0)
+# CHECK-ASM: encoding: [0x2f,0x03,0x05,0x34]
+# CHECK-NO-EXT: error: instruction requires the following: 'Zalasr' (Load-Acquire and Store-Release Instructions){{$}}
+lb.aq t1, 0(a0)
+
+# CHECK-ASM-AND-OBJ: lh.aq t1, (a0)
+# CHECK-ASM: encoding: [0x2f,0x13,0x05,0x34]
+# CHECK-NO-EXT: error: instruction requires the following: 'Zalasr' (Load-Acquire and Store-Release Instructions){{$}}
+lh.aq t1, 0(a0)
+
+# CHECK-ASM-AND-OBJ: lw.aq t1, (a0)
+# CHECK-ASM: encoding: [0x2f,0x23,0x05,0x34]
+# CHECK-NO-EXT: error: instruction requires the following: 'Zalasr' (Load-Acquire and Store-Release Instructions){{$}}
+lw.aq t1, (a0)
+
+# CHECK-ASM-AND-OBJ: lb.aqrl t1, (a0)
+# CHECK-ASM: encoding: [0x2f,0x03,0x05,0x36]
+# CHECK-NO-EXT: error: instruction requires the following: 'Zalasr' (Load-Acquire and Store-Release Instructions){{$}}
+lb.aqrl t1, 0(a0)
+
+# CHECK-ASM-AND-OBJ: lh.aqrl t1, (a0)
+# CHECK-ASM: encoding: [0x2f,0x13,0x05,0x36]
+# CHECK-NO-EXT: error: instruction requires the following: 'Zalasr' (Load-Acquire and Store-Release Instructions){{$}}
+lh.aqrl t1, (a0)
+
+# CHECK-ASM-AND-OBJ: lw.aqrl t1, (a0)
+# CHECK-ASM: encoding: [0x2f,0x23,0x05,0x36]
+# CHECK-NO-EXT: error: instruction requires the following: 'Zalasr' (Load-Acquire and Store-Release Instructions){{$}}
+lw.aqrl t1, (a0)
+
+
+# CHECK-ASM-AND-OBJ: sb.rl t1, (a0)
+# CHECK-ASM: encoding: [0x2f,0x00,0x65,0x3a]
+# CHECK-NO-EXT: error: instruction requires the following: 'Zalasr' (Load-Acquire and Store-Release Instructions){{$}}
+sb.rl t1, (a0)
+
+# CHECK-ASM-AND-OBJ: sh.rl t1, (a0)
+# CHECK-ASM: encoding: [0x2f,0x10,0x65,0x3a]
+# CHECK-NO-EXT: error: instruction requires the following: 'Zalasr' (Load-Acquire and Store-Release Instructions){{$}}
+sh.rl t1, 0(a0)
+
+# CHECK-ASM-AND-OBJ: sw.rl t1, (a0)
+# CHECK-ASM: encoding: [0x2f,0x20,0x65,0x3a]
+# CHECK-NO-EXT: error: instruction requires the following: 'Zalasr' (Load-Acquire and Store-Release Instructions){{$}}
+sw.rl t1, (a0)
+
+# CHECK-ASM-AND-OBJ: sb.aqrl t1, (a0)
+# CHECK-ASM: encoding: [0x2f,0x00,0x65,0x3e]
+# CHECK-NO-EXT: error: instruction requires the following: 'Zalasr' (Load-Acquire and Store-Release Instructions){{$}}
+sb.aqrl t1, (a0)
+
+# CHECK-ASM-AND-OBJ: sh.aqrl t1, (a0)
+# CHECK-ASM: encoding: [0x2f,0x10,0x65,0x3e]
+# CHECK-NO-EXT: error: instruction requires the following: 'Zalasr' (Load-Acquire and Store-Release Instructions){{$}}
+sh.aqrl t1, 0(a0)
+
+# CHECK-ASM-AND-OBJ: sw.aqrl t1, (a0)
+# CHECK-ASM: encoding: [0x2f,0x20,0x65,0x3e]
+# CHECK-NO-EXT: error: instruction requires the following: 'Zalasr' (Load-Acquire and Store-Release Instructions){{$}}
+sw.aqrl t1, 0(a0)
diff --git a/llvm/test/MC/RISCV/rv64zalasr-invalid.s b/llvm/test/MC/RISCV/rv64zalasr-invalid.s
new file mode 100644
index 0000000..032c0c00
--- /dev/null
+++ b/llvm/test/MC/RISCV/rv64zalasr-invalid.s
@@ -0,0 +1,28 @@
+# RUN: not llvm-mc -triple riscv64 -mattr=+experimental-zalasr < %s 2>&1 | FileCheck -check-prefixes=CHECK %s
+
+# CHECK: error: unrecognized instruction mnemonic
+lw. a1, (t0)
+
+# CHECK: error: unrecognized instruction mnemonic
+lw.rl t3, 0(t5)
+
+# CHECK: error: unrecognized instruction mnemonic
+lh.rlaq t4, (t6)
+
+# CHECK: error: unrecognized instruction mnemonic
+sb. a1, (t0)
+
+# CHECK: error: unrecognized instruction mnemonic
+sh.aq t3, 0(t5)
+
+# CHECK: error: unrecognized instruction mnemonic
+sh.rlaq t4, (t6)
+
+# CHECK: error: optional integer offset must be 0
+lw.aq zero, 1(a0)
+
+# CHECK: error: optional integer offset must be 0
+sw.rl t1, 2(s0)
+
+# CHECK: error: optional integer offset must be 0
+sb.aqrl sp, 3(s2)
diff --git a/llvm/test/MC/RISCV/rv64zalasr-valid.s b/llvm/test/MC/RISCV/rv64zalasr-valid.s
new file mode 100644
index 0000000..2f1e381
--- /dev/null
+++ b/llvm/test/MC/RISCV/rv64zalasr-valid.s
@@ -0,0 +1,31 @@
+# RUN: llvm-mc %s -triple=riscv64 -mattr=+experimental-zalasr -riscv-no-aliases -show-encoding \
+# RUN:     | FileCheck -check-prefixes=CHECK-ASM,CHECK-ASM-AND-OBJ %s
+# RUN: llvm-mc -filetype=obj -triple=riscv64 -mattr=+experimental-zalasr < %s \
+# RUN:     | llvm-objdump --mattr=+experimental-zalasr -M no-aliases -d -r - \
+# RUN:     | FileCheck --check-prefix=CHECK-ASM-AND-OBJ %s
+#
+# RUN: not llvm-mc -triple riscv64 \
+# RUN:     -riscv-no-aliases -show-encoding < %s 2>&1 \
+# RUN:     | FileCheck --check-prefixes=CHECK-NO-EXT %s
+
+
+# CHECK-ASM-AND-OBJ: ld.aq t1, (a0)
+# CHECK-ASM: encoding: [0x2f,0x33,0x05,0x34]
+# CHECK-NO-EXT: error: instruction requires the following: 'Zalasr' (Load-Acquire and Store-Release Instructions){{$}}
+ld.aq t1, (a0)
+
+# CHECK-ASM-AND-OBJ: ld.aqrl t1, (a0)
+# CHECK-ASM: encoding: [0x2f,0x33,0x05,0x36]
+# CHECK-NO-EXT: error: instruction requires the following: 'Zalasr' (Load-Acquire and Store-Release Instructions){{$}}
+ld.aqrl t1, 0(a0)
+
+
+# CHECK-ASM-AND-OBJ: sd.rl t1, (a0)
+# CHECK-ASM: encoding: [0x2f,0x30,0x65,0x3a]
+# CHECK-NO-EXT: error: instruction requires the following: 'Zalasr' (Load-Acquire and Store-Release Instructions){{$}}
+sd.rl t1, 0(a0)
+
+# CHECK-ASM-AND-OBJ: sd.aqrl t1, (a0)
+# CHECK-ASM: encoding: [0x2f,0x30,0x65,0x3e]
+# CHECK-NO-EXT: error: instruction requires the following: 'Zalasr' (Load-Acquire and Store-Release Instructions){{$}}
+sd.aqrl t1, (a0)