[Lldb-commits] [lldb] r246955 - Bug 24457 - X87 FPU Special Purpose Registers
Abhishek Aggarwal via lldb-commits
lldb-commits at lists.llvm.org
Mon Sep 7 00:40:18 PDT 2015
Author: abhishek
Date: Mon Sep 7 02:40:16 2015
New Revision: 246955
URL: http://llvm.org/viewvc/llvm-project?rev=246955&view=rev
Log:
Bug 24457 - X87 FPU Special Purpose Registers
Summary:
- For 'register read --all' command on x86_64-Linux Platform:
-- Provide correct values of X87 FPU Special Purpose Registers
-- Both 32-bit & 64-bit inferiors give correct values on this
Platform
- Added a Test Vector:
-- To verify the expected behaviour of the command
Signed-off-by: Abhishek Aggarwal <abhishek.a.aggarwal at intel.com>
Reviewers: ashok.thirumurthi, granata.enrico, tfiala, clayborg
Differential Revision: http://reviews.llvm.org/D12592
Added:
lldb/trunk/test/functionalities/register/a.cpp (with props)
Modified:
lldb/trunk/source/Plugins/Process/Linux/NativeRegisterContextLinux_x86_64.cpp (contents, props changed)
lldb/trunk/source/Plugins/Process/Linux/NativeRegisterContextLinux_x86_64.h
lldb/trunk/test/functionalities/register/Makefile (contents, props changed)
lldb/trunk/test/functionalities/register/TestRegisters.py (contents, props changed)
lldb/trunk/test/functionalities/register/main.cpp (contents, props changed)
Modified: lldb/trunk/source/Plugins/Process/Linux/NativeRegisterContextLinux_x86_64.cpp
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Plugins/Process/Linux/NativeRegisterContextLinux_x86_64.cpp?rev=246955&r1=246954&r2=246955&view=diff
==============================================================================
--- lldb/trunk/source/Plugins/Process/Linux/NativeRegisterContextLinux_x86_64.cpp (original)
+++ lldb/trunk/source/Plugins/Process/Linux/NativeRegisterContextLinux_x86_64.cpp Mon Sep 7 02:40:16 2015
@@ -422,6 +422,10 @@ NativeRegisterContextLinux_x86_64::Nativ
// Clear out the FPR state.
::memset(&m_fpr, 0, sizeof(FPR));
+
+ // Store byte offset of fctrl (i.e. first register of FPR)
+ const RegisterInfo *reg_info_fctrl = GetRegisterInfoByName("fctrl");
+ m_fctrl_offset_in_userarea = reg_info_fctrl->byte_offset;
}
// CONSIDER after local and llgs debugging are merged, register set support can
@@ -559,8 +563,16 @@ NativeRegisterContextLinux_x86_64::ReadR
}
// Get pointer to m_fpr.xstate.fxsave variable and set the data from it.
- assert (reg_info->byte_offset < sizeof(m_fpr));
- uint8_t *src = (uint8_t *)&m_fpr + reg_info->byte_offset;
+
+ // Byte offsets of all registers are calculated wrt 'UserArea' structure.
+ // However, ReadFPR() reads fpu registers {using ptrace(PTRACE_GETFPREGS,..)}
+ // and stores them in 'm_fpr' (of type FPR structure). To extract values of fpu
+ // registers, m_fpr should be read at byte offsets calculated wrt to FPR structure.
+
+ // Since, FPR structure is also one of the member of UserArea structure.
+ // byte_offset(fpu wrt FPR) = byte_offset(fpu wrt UserArea) - byte_offset(fctrl wrt UserArea)
+ assert ( (reg_info->byte_offset - m_fctrl_offset_in_userarea) < sizeof(m_fpr));
+ uint8_t *src = (uint8_t *)&m_fpr + reg_info->byte_offset - m_fctrl_offset_in_userarea;
switch (reg_info->byte_size)
{
case 2:
@@ -620,8 +632,16 @@ NativeRegisterContextLinux_x86_64::Write
else
{
// Get pointer to m_fpr.xstate.fxsave variable and set the data to it.
- assert (reg_info->byte_offset < sizeof(m_fpr));
- uint8_t *dst = (uint8_t *)&m_fpr + reg_info->byte_offset;
+
+ // Byte offsets of all registers are calculated wrt 'UserArea' structure.
+ // However, WriteFPR() takes m_fpr (of type FPR structure) and writes only fpu
+ // registers using ptrace(PTRACE_SETFPREGS,..) API. Hence fpu registers should
+ // be written in m_fpr at byte offsets calculated wrt FPR structure.
+
+ // Since, FPR structure is also one of the member of UserArea structure.
+ // byte_offset(fpu wrt FPR) = byte_offset(fpu wrt UserArea) - byte_offset(fctrl wrt UserArea)
+ assert ( (reg_info->byte_offset - m_fctrl_offset_in_userarea) < sizeof(m_fpr));
+ uint8_t *dst = (uint8_t *)&m_fpr + reg_info->byte_offset - m_fctrl_offset_in_userarea;
switch (reg_info->byte_size)
{
case 2:
Propchange: lldb/trunk/source/Plugins/Process/Linux/NativeRegisterContextLinux_x86_64.cpp
------------------------------------------------------------------------------
svn:executable = *
Modified: lldb/trunk/source/Plugins/Process/Linux/NativeRegisterContextLinux_x86_64.h
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Plugins/Process/Linux/NativeRegisterContextLinux_x86_64.h?rev=246955&r1=246954&r2=246955&view=diff
==============================================================================
--- lldb/trunk/source/Plugins/Process/Linux/NativeRegisterContextLinux_x86_64.h (original)
+++ lldb/trunk/source/Plugins/Process/Linux/NativeRegisterContextLinux_x86_64.h Mon Sep 7 02:40:16 2015
@@ -136,6 +136,7 @@ namespace process_linux {
YMM m_ymm_set;
RegInfo m_reg_info;
uint64_t m_gpr_x86_64[k_num_gpr_registers_x86_64];
+ uint32_t m_fctrl_offset_in_userarea;
// Private member methods.
bool IsRegisterSetAvailable (uint32_t set_index) const;
Modified: lldb/trunk/test/functionalities/register/Makefile
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/test/functionalities/register/Makefile?rev=246955&r1=246954&r2=246955&view=diff
==============================================================================
--- lldb/trunk/test/functionalities/register/Makefile (original)
+++ lldb/trunk/test/functionalities/register/Makefile Mon Sep 7 02:40:16 2015
@@ -1,5 +1,5 @@
LEVEL = ../../make
-CXX_SOURCES := main.cpp
+CXX_SOURCES := main.cpp a.cpp
include $(LEVEL)/Makefile.rules
Propchange: lldb/trunk/test/functionalities/register/Makefile
------------------------------------------------------------------------------
svn:executable = *
Modified: lldb/trunk/test/functionalities/register/TestRegisters.py
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/test/functionalities/register/TestRegisters.py?rev=246955&r1=246954&r2=246955&view=diff
==============================================================================
--- lldb/trunk/test/functionalities/register/TestRegisters.py (original)
+++ lldb/trunk/test/functionalities/register/TestRegisters.py Mon Sep 7 02:40:16 2015
@@ -35,6 +35,13 @@ class RegisterCommandsTestCase(TestBase)
self.buildDefault()
self.fp_register_write()
+ def test_fp_special_purpose_register_read(self):
+ """Test commands that read fpu special purpose registers."""
+ if not self.getArchitecture() in ['amd64', 'i386', 'x86_64']:
+ self.skipTest("This test requires x86 or x86_64 as the architecture for the inferior")
+ self.buildDefault()
+ self.fp_special_purpose_register_read()
+
def test_register_expressions(self):
"""Test expression evaluation with commands related to registers."""
if not self.getArchitecture() in ['amd64', 'i386', 'x86_64']:
@@ -152,6 +159,69 @@ class RegisterCommandsTestCase(TestBase)
self.expect("register read " + register,
substrs = [register + ' = ', new_value])
+ def fp_special_purpose_register_read(self):
+ exe = os.path.join(os.getcwd(), "a.out")
+
+ # Create a target by the debugger.
+ target = self.dbg.CreateTarget(exe)
+ self.assertTrue(target, VALID_TARGET)
+
+ # Find the line number to break inside a.cpp.
+ self.line = line_number('a.cpp', '// Set break point at this line.')
+
+ # Set breakpoint
+ lldbutil.run_break_set_by_file_and_line (self, "a.cpp", self.line, num_expected_locations=1, loc_exact=True)
+
+ # Launch the process, and do not stop at the entry point.
+ self.runCmd ("run", RUN_SUCCEEDED)
+
+ process = target.GetProcess()
+ self.assertTrue(process.GetState() == lldb.eStateStopped,
+ PROCESS_STOPPED)
+
+ thread = process.GetThreadAtIndex(0)
+ self.assertTrue(thread.IsValid(), "current thread is valid")
+
+ currentFrame = thread.GetFrameAtIndex(0)
+ self.assertTrue(currentFrame.IsValid(), "current frame is valid")
+
+ # Extract the value of fstat and ftag flag at the point just before
+ # we start pushing floating point values on st% register stack
+ value = currentFrame.FindValue("fstat", lldb.eValueTypeRegister)
+ error = lldb.SBError()
+ reg_value_fstat_initial = value.GetValueAsUnsigned(error, 0)
+
+ self.assertTrue(error.Success(), "reading a value for fstat")
+ value = currentFrame.FindValue("ftag", lldb.eValueTypeRegister)
+ error = lldb.SBError()
+ reg_value_ftag_initial = value.GetValueAsUnsigned(error, 0)
+
+ self.assertTrue(error.Success(), "reading a value for ftag")
+ fstat_top_pointer_initial = (reg_value_fstat_initial & 0x3800)>>11
+
+ # Execute 'si' aka 'thread step-inst' instruction 5 times and with
+ # every execution verify the value of fstat and ftag registers
+ for x in range(0,5):
+ # step into the next instruction to push a value on 'st' register stack
+ self.runCmd ("si", RUN_SUCCEEDED)
+
+ # Verify fstat and save it to be used for verification in next execution of 'si' command
+ if not (reg_value_fstat_initial & 0x3800):
+ self.expect("register read fstat",
+ substrs = ['fstat' + ' = ', str("0x%0.4x" %((reg_value_fstat_initial & ~(0x3800))| 0x3800))])
+ reg_value_fstat_initial = ((reg_value_fstat_initial & ~(0x3800))| 0x3800)
+ fstat_top_pointer_initial = 7
+ else :
+ self.expect("register read fstat",
+ substrs = ['fstat' + ' = ', str("0x%0.4x" % (reg_value_fstat_initial - 0x0800))])
+ reg_value_fstat_initial = (reg_value_fstat_initial - 0x0800)
+ fstat_top_pointer_initial -= 1
+
+ # Verify ftag and save it to be used for verification in next execution of 'si' command
+ self.expect("register read ftag",
+ substrs = ['ftag' + ' = ', str("0x%0.4x" % (reg_value_ftag_initial | (1<< fstat_top_pointer_initial)))])
+ reg_value_ftag_initial = reg_value_ftag_initial | (1<< fstat_top_pointer_initial)
+
def fp_register_write(self):
exe = os.path.join(os.getcwd(), "a.out")
Propchange: lldb/trunk/test/functionalities/register/TestRegisters.py
------------------------------------------------------------------------------
svn:executable = *
Added: lldb/trunk/test/functionalities/register/a.cpp
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/test/functionalities/register/a.cpp?rev=246955&view=auto
==============================================================================
--- lldb/trunk/test/functionalities/register/a.cpp (added)
+++ lldb/trunk/test/functionalities/register/a.cpp Mon Sep 7 02:40:16 2015
@@ -0,0 +1,40 @@
+//===-- a.cpp ------------------------------------------------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+#include <stdio.h>
+
+long double
+return_long_double (long double value)
+{
+ float a=2, b=4,c=8, d=16, e=32, f=64, k=128, l=256, add=0;
+__asm__ ( "fld %1 ;"
+ "fld %2 ;"
+ "fld %3 ;"
+ "fld %4 ;"
+ "fld %5 ;"
+ "fld %6 ;"
+ "fld %7 ;"
+ "fadd ;" : "=g" (add) : "g" (a), "g" (b), "g" (c), "g" (d), "g" (e), "g" (f), "g" (k), "g" (l) ); // Set break point at this line.
+ return value;
+}
+
+long double
+outer_return_long_double (long double value)
+{
+ long double val = return_long_double(value);
+ val *= 2 ;
+ return val;
+}
+
+long double
+outermost_return_long_double (long double value)
+{
+ long double val = outer_return_long_double(value);
+ val *= 2 ;
+ return val;
+}
Propchange: lldb/trunk/test/functionalities/register/a.cpp
------------------------------------------------------------------------------
svn:executable = *
Modified: lldb/trunk/test/functionalities/register/main.cpp
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/test/functionalities/register/main.cpp?rev=246955&r1=246954&r2=246955&view=diff
==============================================================================
--- lldb/trunk/test/functionalities/register/main.cpp (original)
+++ lldb/trunk/test/functionalities/register/main.cpp Mon Sep 7 02:40:16 2015
@@ -15,6 +15,8 @@
#include <chrono>
#include <thread>
+long double outermost_return_long_double (long double my_long_double);
+
int main (int argc, char const *argv[])
{
#if defined(__linux__)
@@ -32,6 +34,7 @@ int main (int argc, char const *argv[])
char my_string[] = {'a', 'b', 'c', 'd', 'e', 'f', 'g', 0};
double my_double = 1234.5678;
+ long double my_long_double = 1234.5678;
// For simplicity assume that any cmdline argument means wait for attach.
if (argc > 1)
@@ -43,5 +46,6 @@ int main (int argc, char const *argv[])
printf("my_string=%s\n", my_string);
printf("my_double=%g\n", my_double);
+ outermost_return_long_double (my_long_double);
return 0;
}
Propchange: lldb/trunk/test/functionalities/register/main.cpp
------------------------------------------------------------------------------
svn:executable = *
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