Fix ICE with long double after float HFA.

PR target/19357
* config/ia64/ia64.md (movxf): Handle general register source.  Adjust
comment to document why.
* gcc.c-torture/compile/pr19357.c: New test.

From-SVN: r93809

1 files changed, 40 insertions, 5 deletions

diff --git a/gcc/config/ia64/ia64.md b/gcc/config/ia64/ia64.md
index c406a79..b22f49e 100644
--- a/gcc/config/ia64/ia64.md
+++ b/gcc/config/ia64/ia64.md
@@ -685,10 +685,12 @@
   if (GET_CODE (op0) == SUBREG)
     op0 = SUBREG_REG (op0);
 
-  /* We must support XFmode loads into general registers for stdarg/vararg
-     and unprototyped calls.  We split them into DImode loads for convenience.
-     We don't need XFmode stores from general regs, because a stdarg/vararg
-     routine does a block store to memory of unnamed arguments.  */
+  /* We must support XFmode loads into general registers for stdarg/vararg,
+     unprototyped calls, and a rare case where a long double is passed as
+     an argument after a float HFA fills the FP registers.  We split them into
+     DImode loads for convenience.  We also need to support XFmode stores
+     for the last case.  This case does not happen for stdarg/vararg routines,
+     because we do a block store to memory of unnamed arguments.  */
 
   if (GET_CODE (op0) == REG && GR_REGNO_P (REGNO (op0)))
     {
@@ -708,7 +710,6 @@
 	  if (GET_CODE (op1) == SUBREG)
 	    op1 = SUBREG_REG (op1);
 	  else
-	    /* ??? Maybe we should make a SUBREG here?  */
 	    op1 = gen_rtx_REG (TImode, REGNO (op1));
 
 	  emit_move_insn (gen_rtx_REG (TImode, REGNO (op0)), op1);
@@ -743,6 +744,40 @@
       abort ();
     }
 
+  if (GET_CODE (operands[1]) == REG && GR_REGNO_P (REGNO (operands[1])))
+    {
+      /* We're hoping to transform everything that deals with XFmode
+	 quantities and GR registers early in the compiler.  */
+      if (no_new_pseudos)
+	abort ();
+
+      /* Op0 can't be a GR_REG here, as that case is handled above.
+	 If op0 is a register, then we spill op1, so that we now have a
+	 MEM operand.  This requires creating an XFmode subreg of a TImode reg
+	 to force the spill.  */
+      if (register_operand (operands[0], XFmode))
+	{
+	  rtx op1 = gen_rtx_REG (TImode, REGNO (operands[1]));
+	  op1 = gen_rtx_SUBREG (XFmode, op1, 0);
+	  operands[1] = spill_xfmode_operand (op1, 0);
+	}
+
+      else if (GET_CODE (operands[0]) == MEM)
+	{
+	  rtx in[2];
+
+	  in[WORDS_BIG_ENDIAN] = gen_rtx_REG (DImode, REGNO (operands[1]));
+	  in[!WORDS_BIG_ENDIAN] = gen_rtx_REG (DImode, REGNO (operands[1]) + 1);
+
+	  emit_move_insn (adjust_address (operands[0], DImode, 0), in[0]);
+	  emit_move_insn (adjust_address (operands[0], DImode, 8), in[1]);
+	  DONE;
+	}
+
+      else
+	abort ();
+    }
+
   if (! reload_in_progress && ! reload_completed)
     {
       operands[1] = spill_xfmode_operand (operands[1], 0);