Fix float conversions if sign extension in offset would occur

From-SVN: r12977

gcc/config/rs6000/rs6000.md

@@ -3670,7 +3670,7 @@
 
       xop[0] = operands[0];
       xop[1] = (frame_pointer_needed) ? frame_pointer_rtx : stack_pointer_rtx;
-      xop[2] = GEN_INT ((rs6000_fpmem_offset >> 16) & 0xffff);
+      xop[2] = GEN_INT ((rs6000_fpmem_offset >> 16) + ((rs6000_fpmem_offset & 0x8000) >> 15));
       output_asm_insn (\"{cau %0,%2(%1)|addis %0,%1,%2}\", xop);
     }
   else if (rs6000_fpmem_offset < 0)
@@ -3699,7 +3699,7 @@
   operands[2] = gen_rtx (MEM, SImode,
 			 gen_rtx (PLUS, Pmode,
 				  indx,
-				  GEN_INT ((rs6000_fpmem_offset & 0xffff)
+				  GEN_INT ((((rs6000_fpmem_offset & 0xffff) ^ 0x8000) - 0x8000)
 					   + ((WORDS_BIG_ENDIAN != 0) * 4))));
 
   return \"{st|stw} %0,%2\";
@@ -3726,7 +3726,7 @@
   operands[2] = gen_rtx (MEM, SImode,
 			 gen_rtx (PLUS, Pmode,
 				  indx,
-				  GEN_INT ((rs6000_fpmem_offset & 0xffff)
+				  GEN_INT ((((rs6000_fpmem_offset & 0xffff) ^ 0x8000) - 0x8000)
 					   + ((WORDS_BIG_ENDIAN == 0) * 4))));
 
   return \"{st|stw} %0,%2\";
@@ -3746,7 +3746,7 @@
   if (rs6000_fpmem_offset > 32760)
     {
       indx = operands[1];
-      offset &= 0xffff;
+      offset = (((offset & 0xffff) ^ 0x8000) - 0x8000);
     }
   else if (frame_pointer_needed)
     indx = frame_pointer_rtx;
@@ -3836,9 +3836,9 @@
   operands[2] = gen_rtx (MEM, DFmode,
 			 gen_rtx (PLUS, Pmode,
 				  indx,
-				  GEN_INT ((rs6000_fpmem_offset & 0xffff))));
+				  GEN_INT (rs6000_fpmem_offset)));
 
-  return \"stfd %0,%2\";
+  return \"stfd %0,%w2\";
 }"
   [(set_attr "type" "fpstore")])
 
@@ -3861,7 +3861,7 @@
   operands[2] = gen_rtx (MEM, DFmode,
 			 gen_rtx (PLUS, Pmode,
 				  indx,
-				  GEN_INT ((rs6000_fpmem_offset & 0xffff)
+				  GEN_INT ((((rs6000_fpmem_offset & 0xffff) ^ 0x8000) - 0x8000)
 					   + ((WORDS_BIG_ENDIAN) ? 4 : 0))));
 
   return \"{l|lwz} %0,%2\";