From 5a9d543311a8afc0bdd279d11dcf4712988bbd3f Mon Sep 17 00:00:00 2001
From: Sandipan Das <sandipan@linux.ibm.com>
Date: Sat, 6 Feb 2021 17:20:56 +0530
Subject: [PATCH] arch-power: Fix disassembly for compare instructions

This fixes disassembly generated for integer compare
instructions based on the type of operands, the type of
comparison to be made and the special use cases for which
the Power ISA provides extended mnemonics.

Change-Id: Ia052bef9589cc3ed290400390028398be28c8eff
Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/40914
Reviewed-by: Boris Shingarov <shingarov@labware.com>
Maintainer: Boris Shingarov <shingarov@labware.com>
Tested-by: kokoro <noreply+kokoro@google.com>
---
 src/arch/power/insts/integer.cc | 154 +++++++++++++++++++++++++++++++-
 src/arch/power/insts/integer.hh |   9 ++
 2 files changed, 161 insertions(+), 2 deletions(-)

diff --git a/src/arch/power/insts/integer.cc b/src/arch/power/insts/integer.cc
index 61b7f08f22..95de652e8b 100644
--- a/src/arch/power/insts/integer.cc
+++ b/src/arch/power/insts/integer.cc
@@ -49,8 +49,7 @@ IntOp::generateDisassembly(Addr pc, const loader::SymbolTable *symtab) const
                myMnemonic == "mtxer" ||
                myMnemonic == "mtlr"  ||
                myMnemonic == "mtctr" ||
-               myMnemonic == "mttar" ||
-               myMnemonic == "cmpi") {
+               myMnemonic == "mttar") {
         printDest = false;
     } else if (myMnemonic == "mfcr"  ||
                myMnemonic == "mfxer" ||
@@ -274,6 +273,157 @@ IntDispArithOp::generateDisassembly(
 }
 
 
+std::string
+IntCompOp::generateDisassembly(
+        Addr pc, const Loader::SymbolTable *symtab) const
+{
+    std::stringstream ss;
+    bool printFieldPrefix = false;
+    bool printLength = true;
+
+    // Generate the correct mnemonic
+    std::string myMnemonic(mnemonic);
+
+    // Special cases
+    if (myMnemonic == "cmp" ||
+        myMnemonic == "cmpl") {
+        myMnemonic += l ? "d" : "w";
+        printFieldPrefix = true;
+        printLength = false;
+    }
+
+    ccprintf(ss, "%-10s ", myMnemonic);
+
+    // Print the first destination only
+    if (printFieldPrefix) {
+        if (bf > 0)
+            ss << "cr" << (int) bf;
+    } else {
+        ss << (int) bf;
+    }
+
+    // Print the length
+    if (printLength) {
+        if (!printFieldPrefix || bf > 0)
+            ss << ", ";
+        ss << (int) l;
+    }
+
+    // Print the first source register
+    if (_numSrcRegs > 0) {
+        if (!printFieldPrefix || bf > 0 || printLength)
+            ss << ", ";
+        printReg(ss, srcRegIdx(0));
+
+        // Print the second source register
+        if (_numSrcRegs > 1) {
+            ss << ", ";
+            printReg(ss, srcRegIdx(1));
+        }
+    }
+
+    return ss.str();
+}
+
+
+std::string
+IntImmCompOp::generateDisassembly(
+        Addr pc, const Loader::SymbolTable *symtab) const
+{
+    std::stringstream ss;
+    bool printFieldPrefix = false;
+    bool printLength = true;
+
+    // Generate the correct mnemonic
+    std::string myMnemonic(mnemonic);
+
+    // Special cases
+    if (myMnemonic == "cmpi") {
+        myMnemonic = l ? "cmpdi" : "cmpwi";
+        printFieldPrefix = true;
+        printLength = false;
+    }
+
+    ccprintf(ss, "%-10s ", myMnemonic);
+
+    // Print the first destination only
+    if (printFieldPrefix) {
+        if (bf > 0)
+            ss << "cr" << (int) bf;
+    } else {
+        ss << (int) bf;
+    }
+
+    // Print the length
+    if (printLength) {
+        if (!printFieldPrefix || bf > 0)
+            ss << ", ";
+        ss << (int) l;
+    }
+
+    // Print the first source register
+    if (_numSrcRegs > 0) {
+        if (!printFieldPrefix || bf > 0 || printLength)
+            ss << ", ";
+        printReg(ss, srcRegIdx(0));
+    }
+
+    // Print the immediate value
+    ss << ", " << si;
+
+    return ss.str();
+}
+
+
+std::string
+IntImmCompLogicOp::generateDisassembly(
+        Addr pc, const Loader::SymbolTable *symtab) const
+{
+    std::stringstream ss;
+    bool printFieldPrefix = false;
+    bool printLength = true;
+
+    // Generate the correct mnemonic
+    std::string myMnemonic(mnemonic);
+
+    // Special cases
+    if (myMnemonic == "cmpli") {
+        myMnemonic = l ? "cmpldi" : "cmplwi";
+        printFieldPrefix = true;
+        printLength = false;
+    }
+
+    ccprintf(ss, "%-10s ", myMnemonic);
+
+    // Print the first destination only
+    if (printFieldPrefix) {
+        if (bf > 0)
+            ss << "cr" << (int) bf;
+    } else {
+        ss << (int) bf;
+    }
+
+    // Print the length
+    if (printLength) {
+        if (!printFieldPrefix || bf > 0)
+            ss << ", ";
+        ss << (int) l;
+    }
+
+    // Print the first source register
+    if (_numSrcRegs > 0) {
+        if (!printFieldPrefix || bf > 0 || printLength)
+            ss << ", ";
+        printReg(ss, srcRegIdx(0));
+    }
+
+    // Print the immediate value
+    ss << ", " << ui;
+
+    return ss.str();
+}
+
+
 std::string
 IntShiftOp::generateDisassembly(
         Addr pc, const loader::SymbolTable *symtab) const
diff --git a/src/arch/power/insts/integer.hh b/src/arch/power/insts/integer.hh
index 6fb797a95d..64ba635ec6 100644
--- a/src/arch/power/insts/integer.hh
+++ b/src/arch/power/insts/integer.hh
@@ -423,6 +423,9 @@ class IntCompOp : public IntOp
         bf(machInst.bf)
     {
     }
+
+    std::string generateDisassembly(
+            Addr pc, const Loader::SymbolTable *symtab) const override;
 };
 
 
@@ -441,6 +444,9 @@ class IntImmCompOp : public IntCompOp
         si(sext<16>(machInst.si))
     {
     }
+
+    std::string generateDisassembly(
+            Addr pc, const Loader::SymbolTable *symtab) const override;
 };
 
 
@@ -459,6 +465,9 @@ class IntImmCompLogicOp : public IntCompOp
         ui(machInst.ui)
     {
     }
+
+    std::string generateDisassembly(
+            Addr pc, const Loader::SymbolTable *symtab) const override;
 };