gcc/gcc10-pr94254.patch

25 lines
864 B
Diff

2020-03-23 Richard Sandiford <richard.sandiford@arm.com>
PR target/94254
* config/rs6000/rs6000.c (rs6000_can_change_mode_class): Allow
FPRs to change between SDmode and DDmode.
--- gcc/config/rs6000/rs6000.c
+++ gcc/config/rs6000/rs6000.c
@@ -12307,6 +12307,15 @@ rs6000_can_change_mode_class (machine_mode from,
if (!BYTES_BIG_ENDIAN && (to == TDmode || from == TDmode))
return false;
+ /* Allow SD<->DD changes, since SDmode values are stored in
+ the low half of the DDmode, just like target-independent
+ code expects. We need to allow at least SD->DD since
+ rs6000_secondary_memory_needed_mode asks for that change
+ to be made for SD reloads. */
+ if ((to == DDmode && from == SDmode)
+ || (to == SDmode && from == DDmode))
+ return true;
+
if (from_size < 8 || to_size < 8)
return false;