[lldb-server][MIPS] Read/Write FP registers in FR0 mode

    Adding support for read/write FP registers in FR0 mode of mips.

Reviewers: clayborg, tberghammer, jaydeep
Subscribers: emaste, nitesh.jain, bhushan, mohit.bhakkad, lldb-commits
Differential Revision: http://reviews.llvm.org/D10242


git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@239132 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 83 insertions, 4 deletions

diff --git a/source/Plugins/Process/Linux/NativeRegisterContextLinux_mips64.cpp b/source/Plugins/Process/Linux/NativeRegisterContextLinux_mips64.cpp
index 9bce8a80a..ad8b2756c 100644
--- a/source/Plugins/Process/Linux/NativeRegisterContextLinux_mips64.cpp
+++ b/source/Plugins/Process/Linux/NativeRegisterContextLinux_mips64.cpp
@@ -592,6 +592,63 @@ NativeRegisterContextLinux_mips64::WriteAllRegisterValues (const lldb::DataBuffe
     return error;
 }
 
+Error
+NativeRegisterContextLinux_mips64::ReadFPR()
+{
+    void* buf = GetFPRBuffer();
+    if (!buf)
+        return Error("FPR buffer is NULL");
+
+    Error error = NativeRegisterContextLinux::ReadFPR();
+
+    if (IsFR0())
+    {
+         for (int i = 0; i < 16; i++)
+         {
+              // copy odd single from top of neighbouring even double
+              uint8_t * src = (uint8_t *)buf + 4 + (i * 16);
+              uint8_t * dst = (uint8_t *)buf + 8 + (i * 16);
+              *(uint32_t *) dst = *(uint32_t *) src;
+         }
+    }
+
+    return error;
+}
+
+Error
+NativeRegisterContextLinux_mips64::WriteFPR()
+{
+    void* buf = GetFPRBuffer();
+    if (!buf)
+        return Error("FPR buffer is NULL");
+
+    if (IsFR0())
+    {
+         for (int i = 0; i < 16; i++)
+         {
+             // copy odd single to top of neighbouring even double
+             uint8_t * src = (uint8_t *)buf + 8 + (i * 16);
+             uint8_t * dst = (uint8_t *)buf + 4 + (i * 16);
+             *(uint32_t *) dst = *(uint32_t *) src;
+         }
+    }
+
+    return NativeRegisterContextLinux::WriteFPR();
+}
+
+bool
+NativeRegisterContextLinux_mips64::IsFR0()
+{
+    const RegisterInfo *const reg_info_p = GetRegisterInfoAtIndex (36); // Status Register is at index 36 of the register array
+
+    RegisterValue reg_value;
+    ReadRegister (reg_info_p, reg_value);
+
+    uint64_t value = reg_value.GetAsUInt64();
+
+    return (!(value & 0x4000000));
+}
+
 bool
 NativeRegisterContextLinux_mips64::IsFPR(uint32_t reg_index) const
 {
diff --git a/source/Plugins/Process/Linux/NativeRegisterContextLinux_mips64.h b/source/Plugins/Process/Linux/NativeRegisterContextLinux_mips64.h
index 15ff877df..1c24c91c3 100644
--- a/source/Plugins/Process/Linux/NativeRegisterContextLinux_mips64.h
+++ b/source/Plugins/Process/Linux/NativeRegisterContextLinux_mips64.h
@@ -47,6 +47,12 @@ namespace process_linux {
         WriteAllRegisterValues (const lldb::DataBufferSP &data_sp) override;
 
         Error
+        ReadFPR() override;
+
+        Error
+        WriteFPR() override;
+
+        Error
         IsWatchpointHit (uint32_t wp_index, bool &is_hit) override;
 
         Error
@@ -85,6 +91,9 @@ namespace process_linux {
                                        const RegisterValue &value) override;
 
         bool
+        IsFR0();
+
+        bool
         IsFPR(uint32_t reg_index) const;
 
         void*
diff --git a/source/Plugins/Process/Utility/RegisterContextLinux_mips64.cpp b/source/Plugins/Process/Utility/RegisterContextLinux_mips64.cpp
index 3cbb823c6..a762930e8 100644
--- a/source/Plugins/Process/Utility/RegisterContextLinux_mips64.cpp
+++ b/source/Plugins/Process/Utility/RegisterContextLinux_mips64.cpp
@@ -74,6 +74,13 @@ typedef struct _GPR
 #include "RegisterInfos_mips64.h"
 #undef DECLARE_REGISTER_INFOS_MIPS64_STRUCT
 
+//---------------------------------------------------------------------------
+// Include RegisterInfos_mips to declare our g_register_infos_mips structure.
+//---------------------------------------------------------------------------
+#define DECLARE_REGISTER_INFOS_MIPS_STRUCT
+#include "RegisterInfos_mips.h"
+#undef DECLARE_REGISTER_INFOS_MIPS_STRUCT
+
 static const RegisterInfo *
 GetRegisterInfoPtr (const ArchSpec &target_arch)
 {
@@ -81,9 +88,10 @@ GetRegisterInfoPtr (const ArchSpec &target_arch)
     {
         case llvm::Triple::mips64:
         case llvm::Triple::mips64el:
+            return g_register_infos_mips64;
         case llvm::Triple::mips:
         case llvm::Triple::mipsel:
-            return g_register_infos_mips64;
+            return g_register_infos_mips;
         default:
             assert(false && "Unhandled target architecture.");
             return nullptr;
@@ -97,9 +105,10 @@ GetRegisterInfoCount (const ArchSpec &target_arch)
     {
         case llvm::Triple::mips64:
         case llvm::Triple::mips64el:
+            return static_cast<uint32_t> (sizeof (g_register_infos_mips64) / sizeof (g_register_infos_mips64 [0]));
         case llvm::Triple::mips:
         case llvm::Triple::mipsel:
-            return static_cast<uint32_t> (sizeof (g_register_infos_mips64) / sizeof (g_register_infos_mips64 [0]));
+            return static_cast<uint32_t> (sizeof (g_register_infos_mips) / sizeof (g_register_infos_mips [0]));
         default:
             assert(false && "Unhandled target architecture.");
             return 0;
diff --git a/source/Plugins/Process/Utility/RegisterInfos_mips.h b/source/Plugins/Process/Utility/RegisterInfos_mips.h
index ddfb98ab8..0956b2ca9 100644
--- a/source/Plugins/Process/Utility/RegisterInfos_mips.h
+++ b/source/Plugins/Process/Utility/RegisterInfos_mips.h
@@ -26,6 +26,10 @@
       eFormatHex, { kind1, kind2, kind3, kind4, gpr_##reg##_mips }, NULL, NULL }
 
 #define DEFINE_FPR(member, reg, alt, kind1, kind2, kind3, kind4)           \
+    { #reg, alt, sizeof(((FPR_mips*)NULL)->member) / 2, FPR_OFFSET(member), eEncodingUint,   \
+      eFormatHex, { kind1, kind2, kind3, kind4, fpr_##reg##_mips }, NULL, NULL }
+
+#define DEFINE_FPR_INFO(member, reg, alt, kind1, kind2, kind3, kind4)           \
     { #reg, alt, sizeof(((FPR_mips*)NULL)->member), FPR_OFFSET(member), eEncodingUint,   \
       eFormatHex, { kind1, kind2, kind3, kind4, fpr_##reg##_mips }, NULL, NULL }
 
@@ -104,8 +108,8 @@ g_register_infos_mips[] =
     DEFINE_FPR (fp_reg[29],  f29,   NULL,   gcc_dwarf_f29_mips,  gcc_dwarf_f29_mips,  LLDB_INVALID_REGNUM,    gdb_f29_mips),
     DEFINE_FPR (fp_reg[30],  f30,   NULL,   gcc_dwarf_f30_mips,  gcc_dwarf_f30_mips,  LLDB_INVALID_REGNUM,    gdb_f30_mips),
     DEFINE_FPR (fp_reg[31],  f31,   NULL,   gcc_dwarf_f31_mips,  gcc_dwarf_f31_mips,  LLDB_INVALID_REGNUM,    gdb_f31_mips),
-    DEFINE_FPR (fcsr,        fcsr,  NULL,   gcc_dwarf_fcsr_mips, gcc_dwarf_fcsr_mips, LLDB_INVALID_REGNUM,    gdb_fcsr_mips),
-    DEFINE_FPR (fir,         fir,   NULL,   gcc_dwarf_fir_mips,  gcc_dwarf_fir_mips,  LLDB_INVALID_REGNUM,    gdb_fir_mips)
+    DEFINE_FPR_INFO (fcsr,        fcsr,  NULL,   gcc_dwarf_fcsr_mips, gcc_dwarf_fcsr_mips, LLDB_INVALID_REGNUM,    gdb_fcsr_mips),
+    DEFINE_FPR_INFO (fir,         fir,   NULL,   gcc_dwarf_fir_mips,  gcc_dwarf_fir_mips,  LLDB_INVALID_REGNUM,    gdb_fir_mips)
 };
 static_assert((sizeof(g_register_infos_mips) / sizeof(g_register_infos_mips[0])) == k_num_registers_mips,
     "g_register_infos_mips has wrong number of register infos");