openhwgroup · JeanRochCoulon · Nov 12, 2023 · Oct 11, 2023
@@ -1,4 +1,4 @@
-..
+..
    Copyright (c) 2023 OpenHW Group
    Copyright (c) 2023 Thales DIS design services SAS
 
@@ -31,6 +31,7 @@ In this document, we present ISA (Instruction Set Architecture) for C32VA6_v5.0.
 * RV32C        – Standard Extension for Compressed Instructions
 * RV32Zicsr    – Standard Extension for CSR Instructions
 * RV32Zifencei – Standard Extension for Instruction-Fetch Fence
+* RV32Zicond   – Standard Extension for Integer Conditional Operations
 
 The base RISC-V ISA has fixed-length 32-bit instructions or 16-bit instructions (the C32VA6_v5.0.0 support C extension), so that must be naturally aligned on 4-byte boundary or 2-byte boundary.
 The C32VA6_v5.0.0 supports:
@@ -451,7 +452,7 @@ Control Transfer Instructions
     **Format**: beq rs1, rs2, imm[12:1]
 
     **Description**: takes the branch (pc is calculated using signed arithmetic) if registers rs1 and rs2 are equal.
-    
+
     **Pseudocode**: if (x[rs1] == x[rs2]) pc += sext({imm[12:1], 1’b0}) else pc += 4
 
     **Invalid values**: NONE
@@ -465,7 +466,7 @@ Control Transfer Instructions
     **Description**: takes the branch (pc is calculated using signed arithmetic) if registers rs1 and rs2 are not equal.
 
     **Pseudocode**: if (x[rs1] != x[rs2]) pc += sext({imm[12:1], 1’b0}) else pc += 4
-       
+
     **Invalid values**: NONE
 
     **Exception raised**: no instruction fetch misaligned exception is generated for a conditional branch that is not taken. An Instruction address misaligned exception is raised if the target address is not aligned on 4-byte or 2-byte boundary, because the core supports compressed instructions.
@@ -479,7 +480,7 @@ Control Transfer Instructions
     **Pseudocode**: if (x[rs1] < x[rs2]) pc += sext({imm[12:1], 1’b0}) else pc += 4
 
     **Invalid values**: NONE
-    
+
     **Exception raised**: no instruction fetch misaligned exception is generated for a conditional branch that is not taken. An Instruction address misaligned exception is raised if the target address is not aligned on 4-byte or 2-byte boundary, because the core supports compressed instructions.
 
 - **BLTU**: Branch Less Than Unsigned
@@ -513,7 +514,7 @@ Control Transfer Instructions
     **Description**: takes the branch (pc is calculated using signed arithmetic) if registers rs1 is greater than or equal rs2 (using unsigned comparison).
 
     **Pseudocode**: if (x[rs1] >=u x[rs2]) pc += sext({imm[12:1], 1’b0}) else pc += 4
-    
+
     **Invalid values**: NONE
 
     **Exception raised**: no instruction fetch misaligned exception is generated for a conditional branch that is not taken. An Instruction address misaligned exception is raised if the target address is not aligned on 4-byte or 2-byte boundary, because the core supports compressed instructions.
@@ -1343,6 +1344,35 @@ RV32Zifencei Instruction-Fetch Fence
 
     **Exception raised**: NONE
 
+RV32Zicond Integer Conditional operations
+-------------------------------------------
+
+The instructions follow the format for R-type instructions with 3 operands (i.e., 2 source operands and 1 destination operand). Using these instructions, branchless sequences can be implemented (typically in two-instruction sequences) without the need for instruction fusion, special provisions during the decoding of architectural instructions, or other microarchitectural provisions.
+
+- **CZERO.EQZ**: Conditional zero, if condition is equal to zero
+
+    **Format**: czero.eqz rd, rs1, rs2
+
+    **Description**: This instruction behaves as if there is a conditional branch dependent on rs2 being equal to zero, wherein it branches to code that writes a 0 into rd when the equivalence is true, and otherwise falls through to code that moves rs1 into rd.
+
+    **Pseudocode**: if (x[rs2] == 0) x[rd] = 0 else x[rs1]
+
+    **Invalid values**: NONE
+
+    **Exception raised**: NONE
+
+- **CZERO.NEZ**: Conditional zero, if condition is nonzero
+
+    **Format**: czero.nez rd, rs1, rs2
+
+    **Description**: This instruction behaves as if there is a conditional branch dependent on rs2 being not equal to zero, wherein it branches to code that writes a 0 into rd when the equivalence is true, and otherwise falls through to code that moves rs1 into rd
+
+    **Pseudocode**: if (x[rs2] != 0) x[rd] = 0 else x[rs1]
+
+    **Invalid values**: NONE
+
+    **Exception raised**: NONE
+
 Illegal Instruction
 ---------------------------
 

@@ -0,0 +1,142 @@
+!Feature
+next_elt_id: 2
+name: RV32Zicond Integer Conditional Instructions
+id: 16
+display_order: 16
+subfeatures: !!omap
+- 000_CZERO.EQZ: !Subfeature
+    name: 000_CZERO.EQZ
+    tag: VP_ISA_RV32_F016_S000
+    next_elt_id: 3
+    display_order: 0
+    items: !!omap
+    - '000': !VerifItem
+        name: '000'
+        tag: VP_ISA_RV32_F016_S000_I000
+        description: "czero.eqz rd, rs1, rs2\nif (x[rs2] == 0) x[rd] = 0 else x[rs1]\n
+          Set rd's value to zero if rs2 is equal to zero, otherwise moves rs1 into
+          rd"
+        reqt_doc: ./RISCV_Instructions.rst
+        ref_mode: page
+        ref_page: ''
+        ref_section: ''
+        ref_viewer: firefox
+        verif_goals: "Register operands:\n\nAll possible rd registers are used\nAll
+          possible rs1 registers are used\nAll possible rs2 registers are used\nAll
+          possible register combinations where rs1 == rd are used\nAll possible register
+          combinations where rs2 == rd are used"
+        pfc: 3
+        test_type: 3
+        cov_method: 1
+        cores: 56
+        coverage_loc: ''
+        comments: ''
+    - '001': !VerifItem
+        name: '001'
+        tag: VP_ISA_RV32_F016_S000_I001
+        description: "czero.eqz rd, rs1, rs2\nif (x[rs2] == 0) x[rd] = 0 else x[rs1]\n
+          Set rd's value to zero if rs2 is equal to zero, otherwise moves rs1 into
+          rd"
+        reqt_doc: ./RISCV_Instructions.rst
+        ref_mode: page
+        ref_page: ''
+        ref_section: ''
+        ref_viewer: firefox
+        verif_goals: "Input operands:\n\nrs1 value is +ve, -ve and zero\nrs2 value
+          is +ve, -ve and zero\nAll combinations of rs1 and rs2 +ve, -ve, and zero
+          values are used\nAll bits of rs1 are toggled\nAll bits of rs2 are toggled"
+        pfc: -1
+        test_type: -1
+        cov_method: -1
+        cores: 56
+        coverage_loc: ''
+        comments: ''
+    - '002': !VerifItem
+        name: '002'
+        tag: VP_ISA_RV32_F016_S000_I002
+        description: "czero.eqz rd, rs1, rs2\nif (x[rs2] == 0) x[rd] = 0 else x[rs1]\n
+          Set rd's value to zero if rs2 is equal to zero, otherwise moves rs1 into
+          rd"
+        reqt_doc: ./RISCV_Instructions.rst
+        ref_mode: page
+        ref_page: ''
+        ref_section: ''
+        ref_viewer: firefox
+        verif_goals: "Output result:\n\nrd value is +ve, -ve and zero\nAll bits of
+          rd are toggled"
+        pfc: -1
+        test_type: -1
+        cov_method: -1
+        cores: 56
+        coverage_loc: ''
+        comments: ''
+- 001_CZERO.NEZ: !Subfeature
+    name: 001_CZERO.NEZ
+    tag: VP_ISA_RV32_F016_S001
+    next_elt_id: 3
+    display_order: 1
+    items: !!omap
+    - '000': !VerifItem
+        name: '000'
+        tag: VP_ISA_RV32_F016_S001_I000
+        description: "czero.nez rd, rs1, rs2\nif (x[rs2] != 0) x[rd] = 0 else x[rs1]\n
+          Set rd's value to zero if rs2 isn't equal to zero, otherwise moves rs1 into
+          rd"
+        reqt_doc: ./RISCV_Instructions.rst
+        ref_mode: page
+        ref_page: ''
+        ref_section: ''
+        ref_viewer: firefox
+        verif_goals: "Register operands:\n\nAll possible rd registers are used\nAll
+          possible rs1 registers are used\nAll possible rs2 registers are used\nAll
+          possible register combinations where rs1 == rd are used\nAll possible register
+          combinations where rs2 == rd are used"
+        pfc: 3
+        test_type: 3
+        cov_method: 1
+        cores: 56
+        coverage_loc: ''
+        comments: ''
+    - '001': !VerifItem
+        name: '001'
+        tag: VP_ISA_RV32_F016_S001_I001
+        description: "czero.nez rd, rs1, rs2\nif (x[rs2] != 0) x[rd] = 0 else x[rs1]\n
+          Set rd's value to zero if rs2 isn't equal to zero, otherwise moves rs1 into
+          rd"
+        reqt_doc: ./RISCV_Instructions.rst
+        ref_mode: page
+        ref_page: ''
+        ref_section: ''
+        ref_viewer: firefox
+        verif_goals: "Input operands:\n\nrs1 value is +ve, -ve and zero\nrs2 value
+          is +ve, -ve and zero\nAll combinations of rs1 and rs2 +ve, -ve, and zero
+          values are used\nAll bits of rs1 are toggled\nAll bits of rs2 are toggled"
+        pfc: -1
+        test_type: -1
+        cov_method: -1
+        cores: 56
+        coverage_loc: ''
+        comments: ''
+    - '002': !VerifItem
+        name: '002'
+        tag: VP_ISA_RV32_F016_S001_I002
+        description: "czero.nez rd, rs1, rs2\nif (x[rs2] != 0) x[rd] = 0 else x[rs1]\n
+          Set rd's value to zero if rs2 isn't equal to zero, otherwise moves rs1 into
+          rd"
+        reqt_doc: ./RISCV_Instructions.rst
+        ref_mode: page
+        ref_page: ''
+        ref_section: ''
+        ref_viewer: firefox
+        verif_goals: "Output result:\n\nrd value is +ve, -ve and zero\nAll bits of
+          rd are toggled"
+        pfc: -1
+        test_type: -1
+        cov_method: -1
+        cores: 56
+        coverage_loc: ''
+        comments: ''
+vptool_gitrev: '$Id: b0efb3ae3f9057b71a577d43c2b77f1cfb2ef82f $'
+io_fmt_gitrev: '$Id: 7ee5d68801f5498a957bcbe23fcad87817a364c5 $'
+config_gitrev: '$Id: 0422e19126dae20ffc4d5a84e4ce3de0b6eb4eb5 $'
+ymlcfg_gitrev: '$Id: 286c689bd48b7a58f9a37754267895cffef1270c $'