[RISCV] Add support for custom instructions for Sifive S76.

quic-garvgupt · topperc · commit 4c37d30e22ae · 2023-06-26T11:36:00.000-07:00
Support for below instruction is added 1. CFLUSH.D.L1 2. CDISCARD.D.L1 3. CEASE Additionally, Zihintpause extension is added to sifive s76 for pause instruction. Spec - https://sifive.cdn.prismic.io/sifive/767804da-53b2-4893-97d5-b7c030ae0a94_s76mc_core_complex_manual_21G3.pdf Reviewed By: craig.topper Differential Revision: https://reviews.llvm.org/D153370
diff --git a/clang/test/Driver/riscv-cpus.c b/clang/test/Driver/riscv-cpus.c
@@ -112,7 +112,8 @@
 // MCPU-SIFIVE-S76: "-nostdsysteminc" "-target-cpu" "sifive-s76"
 // MCPU-SIFIVE-S76: "-target-feature" "+m" "-target-feature" "+a" "-target-feature" "+f" "-target-feature" "+d"
 // MCPU-SIFIVE-S76: "-target-feature" "+c"
-// MCPU-SIFIVE-S76: "-target-feature" "+zicsr" "-target-feature" "+zifencei"
+// MCPU-SIFIVE-S76: "-target-feature" "+zicsr" "-target-feature" "+zifencei" "-target-feature" "+zihintpause"
+// MCPU-SIFIVE-S76: "-target-feature" "+xsfcie"
 // MCPU-SIFIVE-S76: "-target-abi" "lp64d"
 
 // mcpu with default march
diff --git a/llvm/docs/RISCVUsage.rst b/llvm/docs/RISCVUsage.rst
@@ -273,3 +273,6 @@ The current vendor extensions supported are:
 
 ``XCVmac``
   LLVM implements `version 1.3.1 of the Core-V Multiply-Accumulate (MAC) custom instructions specification <https://github.com/openhwgroup/cv32e40p/blob/4f024fe4b15a68b76615b0630c07a6745c620da7/docs/source/instruction_set_extensions.rst>`_ by Core-V.  All instructions are prefixed with `cv.mac.` as described in the specification. These instructions are only available for riscv32 at this time.
+
+``XSfcie``
+  LLVM implements `version 1.0.0 of the SiFive Custom Instruction Extension (CIE) Software Specification <https://sifive.cdn.prismic.io/sifive/767804da-53b2-4893-97d5-b7c030ae0a94_s76mc_core_complex_manual_21G3.pdf>`_ by SiFive.  All custom instruction are added as described in the specification, and the riscv-toolchain-convention document linked above. These instructions are only available for S76 processor at this time.
diff --git a/llvm/docs/ReleaseNotes.rst b/llvm/docs/ReleaseNotes.rst
@@ -210,6 +210,8 @@ Changes to the RISC-V Backend
   extension disassembler/assembler.
 * Added support for the vendor-defined Xsfvcp (SiFive VCIX) extension
   disassembler/assembler.
+* Added support for the vendor-defined Xsfcie (SiFive CIE) extension
+  disassembler/assembler.
 * Support for the now-ratified Zawrs extension is no longer experimental.
 * Adds support for the vendor-defined XTHeadCmo (cache management operations) extension.
 * Adds support for the vendor-defined XTHeadSync (multi-core synchronization instructions) extension.
diff --git a/llvm/lib/Support/RISCVISAInfo.cpp b/llvm/lib/Support/RISCVISAInfo.cpp
@@ -66,6 +66,7 @@ static const RISCVSupportedExtension SupportedExtensions[] = {
     {"v", RISCVExtensionVersion{1, 0}},
 
     // vendor-defined ('X') extensions
+    {"xsfcie", RISCVExtensionVersion{1, 0}},
     {"xsfvcp", RISCVExtensionVersion{1, 0}},
     {"xtheadba", RISCVExtensionVersion{1, 0}},
     {"xtheadbb", RISCVExtensionVersion{1, 0}},
diff --git a/llvm/lib/Target/RISCV/Disassembler/RISCVDisassembler.cpp b/llvm/lib/Target/RISCV/Disassembler/RISCVDisassembler.cpp
@@ -558,6 +558,8 @@ DecodeStatus RISCVDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
                           "XTHeadVdot custom opcode table");
     TRY_TO_DECODE_FEATURE(RISCV::FeatureVendorXSfvcp, DecoderTableXSfvcp32,
                           "SiFive VCIX custom opcode table");
+    TRY_TO_DECODE_FEATURE(RISCV::FeatureVendorXSfcie, DecoderTableXSfcie32,
+                          "Sifive CIE custom opcode table");
     TRY_TO_DECODE_FEATURE(RISCV::FeatureVendorXCVbitmanip,
                           DecoderTableXCVbitmanip32,
                           "CORE-V Bit Manipulation custom opcode table");
diff --git a/llvm/lib/Target/RISCV/RISCVFeatures.td b/llvm/lib/Target/RISCV/RISCVFeatures.td
@@ -752,6 +752,12 @@ def HasVendorXSfvcp : Predicate<"Subtarget->hasVendorXSfvcp()">,
                                 AssemblerPredicate<(all_of FeatureVendorXSfvcp),
                                 "'XSfvcp' (SiFive Custom Vector Coprocessor Interface Instructions)">;
 
+def FeatureVendorXSfcie
+    : SubtargetFeature<"xsfcie", "HasVendorXSfcie", "true",
+                       "'XSfcie' (SiFive Custom Instruction Extension SCIE.)">;
+def HasVendorXSfcie : Predicate<"Subtarget->hasVendorXSfcie()">,
+                        AssemblerPredicate<(all_of FeatureVendorXSfcie),
+                        "'XSfcie' (SiFive Custom Instruction Extension SCIE.)">;
 
 def FeatureVendorXCVbitmanip
     : SubtargetFeature<"xcvbitmanip", "HasVendorXCVbitmanip", "true",
diff --git a/llvm/lib/Target/RISCV/RISCVInstrInfoXSf.td b/llvm/lib/Target/RISCV/RISCVInstrInfoXSf.td
@@ -504,3 +504,27 @@ let Predicates = [HasVendorXSfvcp] in {
     }
   }
 }
+
+let Predicates = [HasVendorXSfcie] in {
+let hasSideEffects = 1, mayLoad = 0, mayStore = 0, DecoderNamespace = "XSfcie" in {
+def SF_CFLUSH_D_L1 : RVInstI<0b000, OPC_SYSTEM, (outs), (ins GPR:$rs1), "cflush.d.l1","$rs1">,
+                             Sched<[]> {
+  let rd = 0;
+  let imm12 = {0b1111,0b1100,0b0000};
+}
+
+def SF_CDISCARD_D_L1 : RVInstI<0b000, OPC_SYSTEM, (outs), (ins GPR:$rs1), "cdiscard.d.l1","$rs1">,
+                               Sched<[]> {
+  let rd = 0;
+  let imm12 = {0b1111,0b1100,0b0010};
+}
+
+def SF_CEASE : RVInstI<0b000, OPC_SYSTEM, (outs), (ins), "cease","">,  Sched<[]> {
+  let rs1 = 0;
+  let rd = 0;
+  let imm12 = {0b0011,0b0000,0b0101};
+}
+}
+def : InstAlias<"cflush.d.l1", (SF_CFLUSH_D_L1 X0)>;
+def : InstAlias<"cdiscard.d.l1", (SF_CDISCARD_D_L1 X0)>;
+} // Predicates = [HasVendorXScie]
diff --git a/llvm/lib/Target/RISCV/RISCVProcessors.td b/llvm/lib/Target/RISCV/RISCVProcessors.td
@@ -142,7 +142,9 @@ def SIFIVE_S76 : RISCVProcessorModel<"sifive-s76",
                                       FeatureStdExtA,
                                       FeatureStdExtF,
                                       FeatureStdExtD,
-                                      FeatureStdExtC],
+                                      FeatureStdExtC,
+                                      FeatureStdExtZihintpause,
+                                      FeatureVendorXSfcie],
                                      [TuneSiFive7]>;
 
 def SIFIVE_U54 : RISCVProcessorModel<"sifive-u54",
diff --git a/llvm/test/MC/RISCV/attribute-arch.s b/llvm/test/MC/RISCV/attribute-arch.s
@@ -278,3 +278,6 @@
 
 .attribute arch, "rv32i_zvfbfwma0p6"
 # CHECK: .attribute     5, "rv32i2p1_f2p2_zicsr2p0_zve32f1p0_zve32x1p0_zvfbfwma0p6_zvl32b1p0"
+
+.attribute arch, "rv64i_xsfcie"
+# CHECK: attribute      5, "rv64i2p1_xsfcie1p0"
diff --git a/llvm/test/MC/RISCV/xsfcie-invalid.s b/llvm/test/MC/RISCV/xsfcie-invalid.s
@@ -0,0 +1,25 @@
+# SCIE - SiFive Custom Instructions Extension.
+# RUN: not llvm-mc -triple riscv32 -mattr=-xsfcie < %s 2>&1 | FileCheck %s
+# RUN: not llvm-mc -triple riscv64 -mattr=-xsfcie < %s 2>&1 | FileCheck %s
+
+cflush.d.l1 0x10 # CHECK: :[[@LINE]]:13: error: invalid operand for instruction
+
+cdiscard.d.l1 0x10 # CHECK: :[[@LINE]]:15: error: invalid operand for instruction
+
+cflush.d.l1 # CHECK: :[[@LINE]]:1: error: instruction requires the following: 'XSfcie' (SiFive Custom Instruction Extension SCIE.)
+
+cdiscard.d.l1 # CHECK: :[[@LINE]]:1: error: instruction requires the following: 'XSfcie' (SiFive Custom Instruction Extension SCIE.)
+
+cflush.d.l1 x0 # CHECK: :[[@LINE]]:1: error: instruction requires the following: 'XSfcie' (SiFive Custom Instruction Extension SCIE.)
+
+cflush.d.l1 x7 # CHECK: :[[@LINE]]:1: error: instruction requires the following: 'XSfcie' (SiFive Custom Instruction Extension SCIE.)
+
+cdiscard.d.l1 x0 # CHECK: :[[@LINE]]:1: error: instruction requires the following: 'XSfcie' (SiFive Custom Instruction Extension SCIE.)
+
+cdiscard.d.l1 x7 # CHECK: :[[@LINE]]:1: error: instruction requires the following: 'XSfcie' (SiFive Custom Instruction Extension SCIE.)
+
+cease x1 # CHECK: :[[@LINE]]:7: error: invalid operand for instruction
+
+cease 0x10 # CHECK: :[[@LINE]]:7: error: invalid operand for instruction
+
+cease # CHECK: :[[@LINE]]:1: error: instruction requires the following: 'XSfcie' (SiFive Custom Instruction Extension SCIE.)
diff --git a/llvm/test/MC/RISCV/xsfcie-valid.s b/llvm/test/MC/RISCV/xsfcie-valid.s
@@ -0,0 +1,42 @@
+# SCIE - SiFive Custom Instructions Extension.
+# RUN: llvm-mc %s -triple=riscv32 -mattr=+xsfcie -riscv-no-aliases -show-encoding \
+# RUN:     | FileCheck -check-prefixes=CHECK-ENC,CHECK-INST %s
+# RUN: llvm-mc %s -triple=riscv64 -mattr=+xsfcie -riscv-no-aliases -show-encoding \
+# RUN:     | FileCheck -check-prefixes=CHECK-ENC,CHECK-INST %s
+# RUN: llvm-mc -filetype=obj -triple riscv32 -mattr=+xsfcie < %s \
+# RUN:     | llvm-objdump --mattr=+xsfcie -M no-aliases -d - \
+# RUN:     | FileCheck -check-prefix=CHECK-INST %s
+# RUN: llvm-mc -filetype=obj -triple riscv64 -mattr=+xsfcie < %s \
+# RUN:     | llvm-objdump --mattr=+xsfcie -M no-aliases -d - \
+# RUN:     | FileCheck -check-prefix=CHECK-INST %s
+# RUN: llvm-mc %s -triple=riscv64 -mcpu=sifive-s76 -riscv-no-aliases -show-encoding \
+# RUN:     | FileCheck -check-prefixes=CHECK-ENC,CHECK-INST %s
+# RUN: llvm-mc -filetype=obj -triple riscv64 -mcpu=sifive-s76 < %s \
+# RUN:     | llvm-objdump --mcpu=sifive-s76 -M no-aliases -d - \
+# RUN:     | FileCheck -check-prefix=CHECK-INST %s
+
+# CHECK-INST: cflush.d.l1     zero
+# CHECK-ENC: encoding: [0x73,0x00,0x00,0xfc]
+# CHECK-INST: cflush.d.l1     zero
+# CHECK-ENC: encoding: [0x73,0x00,0x00,0xfc]
+cflush.d.l1 x0
+cflush.d.l1
+
+# CHECK-INST: cflush.d.l1     t2
+# CHECK-ENC: encoding: [0x73,0x80,0x03,0xfc]
+cflush.d.l1 x7
+
+# CHECK-INST: cdiscard.d.l1   zero
+# CHECK-ENC: encoding: [0x73,0x00,0x20,0xfc]
+# CHECK-INST: cdiscard.d.l1     zero
+# CHECK-ENC: encoding: [0x73,0x00,0x20,0xfc]
+cdiscard.d.l1 x0
+cdiscard.d.l1
+
+# CHECK-INST: cdiscard.d.l1   t2
+# CHECK-ENC: encoding: [0x73,0x80,0x23,0xfc]
+cdiscard.d.l1 x7
+
+# CHECK-INST: cease
+# CHECK-ENC: encoding: [0x73,0x00,0x50,0x30]
+cease
