Round up the SSE register save area only if needed

There is is no point to round up the SSE register save area to 16 bytes if
the incoming stack boundary is less than 16 bytes.

	* config/i386/i386.c (ix86_compute_frame_layout): Round up the
	SSE register save area to 16 bytes only if the incoming stack
	boundary is no less than 16 bytes.

From-SVN: r228621

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 9f84b6ef8372ad11f44f988ec0a00983cde3f668..428649149456d6d84437bbada6d172eef9254a93 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2015-10-08  H.J. Lu  <hongjiu.lu@intel.com>
+
+       * config/i386/i386.c (ix86_compute_frame_layout): Round up the
+       SSE register save area to 16 bytes only if the incoming stack
+       boundary is no less than 16 bytes.
+
 2015-10-08  Jeff Law  <law@redhat.com>
 
        * tree-ssa-phiopt.c (factor_out_conversion): Add missing calls to

diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index a24bd26c96a05d8e5aae4049cab4901943b78d59..4806a7cffa2950fc6dc36f98174a0597d3f4f33b 100644 (file)
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -11383,9 +11383,14 @@ ix86_compute_frame_layout (struct ix86_frame *frame)
   if (frame->nsseregs)
     {
       /* The only ABI that has saved SSE registers (Win64) also has a
-         16-byte aligned default stack, and thus we don't need to be
-        within the re-aligned local stack frame to save them.  */
-      offset = ROUND_UP (offset, 16);
+        16-byte aligned default stack, and thus we don't need to be
+        within the re-aligned local stack frame to save them.  In case
+        incoming stack boundary is aligned to less than 16 bytes,
+        unaligned move of SSE register will be emitted, so there is
+        no point to round up the SSE register save area outside the
+        re-aligned local stack frame to 16 bytes.  */
+      if (ix86_incoming_stack_boundary >= 128)
+       offset = ROUND_UP (offset, 16);
       offset += frame->nsseregs * 16;
     }
   frame->sse_reg_save_offset = offset;