Merge pull request #60 from techiepriyansh/multiple-sigs-per-covpt

Implement capturing multiple signature updates per coverpoint

CHANGELOG.md

@@ -3,6 +3,10 @@
 This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 
+## [0.17.0] - 2022-10-25
+- Improve data propagation reports to capture multiple signature updates per coverpoint
+- Add a CLI flag to explicitly log the redundant coverpoints while normalizing the CGF files
+
 ## [0.16.1] - 2022-10-20
 - Fix length of commitval to 32 bits if flen is 32 for f registers in sail parser.
 

docs/source/cgf.rst

@@ -334,7 +334,11 @@ A covergroup contains the following nodes:
         * **csrcomb-str**  
             This string is interpreted as a valid python statement/expression which evaluates to a Boolean value. The variables available for use in the expression are as follows:
 
-                * ``csr_name`` : The value (as of the end of previous instruction) in the CSR whose name is specified by csr_name.
+                * ``csr_name`` : The value (as of the end of current instruction) in the CSR whose name is specified by csr_name.
+
+                * ``old("csr_name")`` : The value (as of the end of previous instruction) in the CSR whose name is specified by csr_name.
+
+                * ``write("csr_name")`` : The value being written to the CSR in the current instruction whose name is specified by csr_name.
 
                 * ``xlen`` : The length of the regsiters in the machine.
 
@@ -367,6 +371,12 @@ A covergroup contains the following nodes:
 
                     mstatus && (0x8) == 0x8
 
+            4. A coverpoint which checks whether the *M* bit of the value being written to *misa* register is unset and the final value that the register assumes has that bit still set.
+
+                .. code-block:: python
+
+                    (write("misa") >> 12) & 1 == 0 and misa & 0x1000 == 0x1000
+
 * **cross_comb**
     *This node is optional.*
 

docs/source/dpr.rst

@@ -0,0 +1,12 @@
+***********************
+Data Propagation Report
+***********************
+
+The data propagation details quality analysis on the data propagation occurring within the test/application. It reports
+the following statistics about coverpoint hits and related signature updates:
+
+* **STAT1** : Number of instructions that hit unique coverpoints and update the signature
+* **STAT2** : Number of instructions that hit covepoints which are not unique but still update the signature (completely or partially)
+* **STAT3** : Number of instructions that hit a unique coverpoint but do not update the signature completely
+* **STAT4** : Number of multiple signature updates for the same coverpoint
+* **STAT5** : Number of times the signature was overwritten

riscv_isac/InstructionObject.py

@@ -1,6 +1,17 @@
 import struct
 
-
+instrs_sig_mutable = ['auipc','jal','jalr']
+instrs_sig_update = ['sh','sb','sw','sd','c.sw','c.sd','c.swsp','c.sdsp','fsw','fsd',\
+        'c.fsw','c.fsd','c.fswsp','c.fsdsp']
+instrs_no_reg_tracking = ['beq','bne','blt','bge','bltu','bgeu','fence','c.j','c.jal','c.jalr',\
+        'c.jr','c.beqz','c.bnez', 'c.ebreak'] + instrs_sig_update
+instrs_fcsr_affected = ['fmadd.s','fmsub.s','fnmsub.s','fnmadd.s','fadd.s','fsub.s','fmul.s','fdiv.s',\
+        'fsqrt.s','fmin.s','fmax.s','fcvt.w.s','fcvt.wu.s','feq.s','flt.s',\
+        'fle.s','fcvt.s.w','fcvt.s.wu','fcvt.l.s','fcvt.lu.s','fcvt.s.l',\
+        'fcvt.s.lu', 'fmadd.d','fmsub.d','fnmsub.d','fnmadd.d','fadd.d','fsub.d',\
+        'fmul.d','fdiv.d','fsqrt.d','fmin.d','fmax.d','fcvt.s.d','fcvt.d.s',\
+        'feq.d','flt.d','fle.d','fcvt.w.d','fcvt.wu.d','fcvt.l.d','fcvt.lu.d',\
+        'fcvt.d.l','fcvt.d.lu']
 unsgn_rs1 = ['sw','sd','sh','sb','ld','lw','lwu','lh','lhu','lb', 'lbu','flw','fld','fsw','fsd',\
         'bgeu', 'bltu', 'sltiu', 'sltu','c.lw','c.ld','c.lwsp','c.ldsp',\
         'c.sw','c.sd','c.swsp','c.sdsp','mulhu','divu','remu','divuw',\
@@ -112,6 +123,10 @@ def __init__(
         self.rd_nregs = 1
 
 
+    def is_sig_update(self):
+        return self.instr_name in instrs_sig_update
+
+
     def evaluate_instr_vars(self, xlen, flen, arch_state, csr_regfile, instr_vars):
         '''
         This function populates the provided instr_vars dictionary
@@ -179,6 +194,84 @@ def evaluate_instr_vars(self, xlen, flen, arch_state, csr_regfile, instr_vars):
             instr_vars.update(ext_specific_vars)
 
 
+    def get_elements_to_track(self, xlen):
+        '''
+        This function returns the elements to track to aid in monitoring signature updates and related statistics.
+        The returned value is a tuple of three elements:
+
+        - The first element is a list of registers to track whose values cannot be modified before storing
+        - The second element is a list of registers to track whose value can be modified prior to storing
+        - The third element is a list of instructions to track for signature updates other than those of tracked registers (mostly used for branch instructions)
+        '''
+        regs_to_track_immutable = []
+        regs_to_track_mutable = []
+        instrs_to_track = []
+
+        if self.instr_name in instrs_no_reg_tracking:
+            store_instrs = []
+            if self.is_sig_update():
+                store_instrs = [self.instr_name]
+            else:
+                if self.instr_name.startswith("c."):
+                    store_instrs = ['sd','c.sdsp'] if xlen == 64 else ['sw','c.swsp']
+                else:
+                    store_instrs = ['sd'] if xlen == 64 else ['sw']
+            instrs_to_track.append(store_instrs)
+        elif self.instr_name in instrs_sig_mutable:
+            if self.rd is not None:
+                reg = self.rd[1] + str(self.rd[0])
+                regs_to_track_mutable.append(reg)
+        else:
+            if self.rd is not None:
+                reg = self.rd[1] + str(self.rd[0])
+                regs_to_track_immutable.append(reg)
+
+            if self.instr_name in instrs_fcsr_affected:
+                regs_to_track_immutable.append('fcsr')
+
+            if self.csr_commit is not None:
+                for commit in self.csr_commit:
+                    if commit[0] == "CSR":
+                        csr_reg = commit[1]
+                        if csr_reg not in regs_to_track_immutable:
+                            regs_to_track_immutable.append(csr_reg)
+
+        return (regs_to_track_immutable, regs_to_track_mutable, instrs_to_track)
+
+
+    def get_changed_regs(self, arch_state, csr_regfile):
+        '''
+        This function returns a list of registers whose value will be changed as
+        a result of executing this instruction.
+
+        :param csr_regfile: Architectural state of CSR register files
+        :param instr_vars: Dictionary to be populated by the evaluated instruction variables
+        '''
+        changed_regs = []
+
+        if self.reg_commit is not None:
+            reg = self.reg_commit[0] + self.reg_commit[1]
+
+            prev_value = None
+            if self.reg_commit[0] == 'x':
+                prev_value = arch_state.x_rf[int(self.reg_commit[1])]
+            elif self.reg_commit[0] == 'f':
+                prev_value = arch_state.f_rf[int(self.reg_commit[1])]
+
+            if prev_value != str(self.reg_commit[2][2:]): # this is a string check, but should we do an exact number check?
+                changed_regs.append(reg)
+
+        if self.csr_commit is not None:
+            for commit in self.csr_commit:
+                if commit[0] == "CSR":
+                    csr_reg = commit[1]
+
+                    if csr_regfile[csr_reg] != str(commit[2][2:]):
+                        changed_regs.append(csr_reg)
+
+        return changed_regs
+
+
     def update_arch_state(self, arch_state, csr_regfile):
         '''
         This function updates the arch state and csr regfiles

riscv_isac/__init__.py

@@ -4,5 +4,5 @@
 
 __author__ = """InCore Semiconductors Pvt Ltd"""
 __email__ = 'info@incoresemi.com'
-__version__ = '0.16.1'
+__version__ = '0.17.0'
 

riscv_isac/cgf_normalize.py

@@ -549,7 +549,7 @@ def alternate(var, size, signed=True, fltr_func=None,scale_func=None):
     #return [(coverpoint,"Alternate") for coverpoint in coverpoints]
 
 
-def expand_cgf(cgf_files, xlen,flen):
+def expand_cgf(cgf_files, xlen,flen, log_redundant=False):
     '''
     This function will replace all the abstract functions with their unrolled
     coverpoints. It replaces node
@@ -616,6 +616,8 @@ def expand_cgf(cgf_files, xlen,flen):
                                         +" in "+labels+": "+str(e) )
                             else:
                                 for cp,comment in exp_cp:
+                                    if log_redundant and cp in cgf[labels][label]:
+                                        logger.warn(f'Redundant coverpoint during normalization: {cp}')
                                     cgf[labels][label].insert(l+i,cp,coverage,comment=comment)
                                     i += 1
     return dict(cgf)

riscv_isac/constants.py

@@ -9,9 +9,9 @@
 dpr_template = '''
 # Data Propagation Report
 
-- **STAT1** : Number of instructions that hit unique coverpoints and update the signature.
-- **STAT2** : Number of instructions that hit covepoints which are not unique but still update the signature
-- **STAT3** : Number of instructions that hit a unique coverpoint but do not update signature
+- **STAT1** : Number of instructions that hit unique coverpoints and update the signature
+- **STAT2** : Number of instructions that hit covepoints which are not unique but still update the signature (completely or partially)
+- **STAT3** : Number of instructions that hit a unique coverpoint but do not update the signature completely
 - **STAT4** : Number of multiple signature updates for the same coverpoint
 - **STAT5** : Number of times the signature was overwritten
 
@@ -57,10 +57,15 @@
 
 ## Details of STAT1:
 
-- The first column indicates the signature address and the data at that location in hexadecimal in the following format: 
+- The first column indicates the signature address(es) and the data at that location in hexadecimal in the following format:
   ```
-  [Address]
-  Data
+  [Address1]
+  Data1
+
+  [Address2]
+  Data2
+
+  ...
   ```
 
 - The second column captures all the coverpoints which have been captured by that particular signature location