[PATCH 04/12] x86: Avoid stack realignment when copying data

[H.J. Lu via Gcc-patches]

Pass UNITS_PER_WORD * BITS_PER_UNIT to force_reg, when copying data from
one memory location to another with vector registers, to avoid stack
realignment.

        * config/i386/i386-expand.c (ix86_expand_vector_move): Pass
        UNITS_PER_WORD * BITS_PER_UNIT to force_reg when copying data
        from one memory location to another.
---
 gcc/config/i386/i386-expand.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/gcc/config/i386/i386-expand.c b/gcc/config/i386/i386-expand.c
index 1942b46efbf..b3c9b94f717 100644
--- a/gcc/config/i386/i386-expand.c
+++ b/gcc/config/i386/i386-expand.c
@@ -431,7 +431,12 @@ ix86_expand_vector_move (machine_mode mode, rtx operands[])
       && !register_operand (op0, mode)
       && !register_operand (op1, mode))
     {
-      emit_move_insn (op0, force_reg (GET_MODE (op0), op1));
+      /* NB: Don't increase stack alignment requirement when forcing
+        operand1 into a pseudo register to copy data from one memory
+        location to another since it doen't require spill.  */
+      emit_move_insn (op0,
+                     force_reg (GET_MODE (op0), op1,
+                                (UNITS_PER_WORD * BITS_PER_UNIT)));
       return;
     }
 
-- 
2.31.1