Re: [patch] i386-nto-tdep.c: Add support for xmm registers.

[Aleksandar Ristovski <aristovski at qnx dot com>]

Thank you for reviewing the patch!

Joel Brobecker wrote:
> > Add support for XMM registers.
> > * i386-nto-tdep.c (i386_nto_target): Remove definition.
> > (i386nto_regset_id): Add case for SSE register set.
> > (i386nto_register_area): Correctly calculate offsets and sizes for all 
> > supported registers.
> > (I386_NTO_SIGCONTEXT_OFFSET): Remove macro definition.
> > (i386nto_sigcontext_addr): Use better method of retrieving sigcontext 
> > pointer.
> > (init_i386nto_ops): Remove i386_nto_target.
> > (i386nto_init_abi): Remove nto_svr4_so_ops indirection. Properly setup 
> > tdep params sc_reg_offset and sc_num_regs. Remove nto_svr4_so_ops and 
> > make changes accordingly.
>
> I won't pretend I understand everything you do in this patch, but
> the pieces that are related to registers and sigcontext seem to be
> sensible.
>
> However, I found a few hunks which I think are not related to XMM
> register support, but rather to shared library support...

Attached is "clean" XMM support patch.

Thanks,

--
Aleksandar Ristovski
QNX Software Systems

ChangeLog:


	Add support for XMM registers.
	* i386-nto-tdep.c (i386nto_regset_id): Add case for SSE 
register set.
	(i386nto_register_area): Correctly calculate offsets and 
sizes for
	all supported registers.

Index: gdb/i386-nto-tdep.c
===================================================================
RCS file: /cvs/src/src/gdb/i386-nto-tdep.c,v
retrieving revision 1.32
diff -u -p -r1.32 i386-nto-tdep.c
--- gdb/i386-nto-tdep.c	22 Feb 2009 01:02:17 -0000	1.32
+++ gdb/i386-nto-tdep.c	11 Jun 2009 15:25:14 -0000
@@ -126,6 +126,8 @@ i386nto_regset_id (int regno)
     return NTO_REG_GENERAL;
   else if (regno < I386_NUM_GREGS + I386_NUM_FREGS)
     return NTO_REG_FLOAT;
+  else if (regno < I386_SSE_NUM_REGS)
+    return NTO_REG_FLOAT; /* We store xmm registers in fxsave_area.  */
 
   return -1;			/* Error.  */
 }
@@ -134,6 +136,7 @@ static int
 i386nto_register_area (struct gdbarch *gdbarch,
 		       int regno, int regset, unsigned *off)
 {
+  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
   int len;
 
   *off = 0;
@@ -149,30 +152,100 @@ i386nto_register_area (struct gdbarch *g
     }
   else if (regset == NTO_REG_FLOAT)
     {
-      unsigned off_adjust, regsize, regset_size;
+      unsigned off_adjust, regsize, regset_size, regno_base;
+      /* The following are flags indicating number in our fxsave_area.  */
+      int first_four = (regno >= I387_FCTRL_REGNUM (tdep)
+			&& regno <= I387_FISEG_REGNUM (tdep));
+      int second_four = (regno > I387_FISEG_REGNUM (tdep)
+			 && regno <= I387_FOP_REGNUM (tdep));
+      int st_reg = (regno >= I387_ST0_REGNUM (tdep)
+		    && regno < I387_ST0_REGNUM (tdep) + 8);
+      int xmm_reg = (regno >= I387_XMM0_REGNUM (tdep)
+		     && regno < I387_MXCSR_REGNUM (tdep));
 
       if (nto_cpuinfo_valid && nto_cpuinfo_flags | X86_CPU_FXSR)
 	{
 	  off_adjust = 32;
 	  regsize = 16;
 	  regset_size = 512;
+	  /* fxsave_area structure.  */
+	  if (first_four)
+	    {
+	      /* fpu_control_word, fpu_status_word, fpu_tag_word, fpu_operand
+	         registers.  */
+	      regsize = 2; /* Two bytes each.  */
+	      off_adjust = 0;
+	      regno_base = I387_FCTRL_REGNUM (tdep);
+	    }
+	  else if (second_four)
+	    {
+	      /* fpu_ip, fpu_cs, fpu_op, fpu_ds registers.  */
+	      regsize = 4;
+	      off_adjust = 8;
+	      regno_base = I387_FISEG_REGNUM (tdep) + 1;
+	    }
+	  else if (st_reg)
+	    {
+	      /* ST registers.  */
+	      regsize = 16;
+	      off_adjust = 32;
+	      regno_base = I387_ST0_REGNUM (tdep);
+	    }
+	  else if (xmm_reg)
+	    {
+	      /* XMM registers.  */
+	      regsize = 16;
+	      off_adjust = 160;
+	      regno_base = I387_XMM0_REGNUM (tdep);
+	    }
+	  else if (regno == I387_MXCSR_REGNUM (tdep))
+	    {
+	      regsize = 4;
+	      off_adjust = 24;
+	      regno_base = I387_MXCSR_REGNUM (tdep);
+	    }
+	  else
+	    {
+	      /* Whole regset.  */
+	      gdb_assert (regno == -1);
+	      off_adjust = 0;
+	      regno_base = 0;
+	      regsize = regset_size;
+	    }
 	}
       else
 	{
-	  off_adjust = 28;
-	  regsize = 10;
-	  regset_size = 128;
+	  regset_size = 108;
+	  /* fsave_area structure.  */
+	  if (first_four || second_four)
+	    {
+	      /* fpu_control_word, ... , fpu_ds registers.  */
+	      regsize = 4;
+	      off_adjust = 0;
+	      regno_base = I387_FCTRL_REGNUM (tdep);
+	    }
+	  else if (st_reg)
+	    {
+	      /* One of ST registers.  */
+	      regsize = 10;
+	      off_adjust = 7 * 4;
+	      regno_base = I387_ST0_REGNUM (tdep);
+	    }
+	  else
+	    {
+	      /* Whole regset.  */
+	      gdb_assert (regno == -1);
+	      off_adjust = 0;
+	      regno_base = 0;
+	      regsize = regset_size;
+	    }
 	}
 
-      if (regno == -1)
-	return regset_size;
-
-      *off = (regno - gdbarch_fp0_regnum (gdbarch)) * regsize + off_adjust;
-      return 10;
-      /* Why 10 instead of regsize?  GDB only stores 10 bytes per FP
-         register so if we're sending a register back to the target,
-         we only want pdebug to write 10 bytes so as not to clobber
-         the reserved 6 bytes in the fxsave structure.  */
+      if (regno != -1)
+	*off = off_adjust + (regno - regno_base) * regsize;
+      else
+	*off = 0;
+      return regsize;
     }
   return -1;
 }