PR middle-end/78468

	* emit-rtl.c (init_emit): Remove ??? comment.
	* explow.c (get_dynamic_stack_size): Take known alignment of stack
	pointer + STACK_DYNAMIC_OFFSET into account in lieu of STACK_BOUNDARY.
	* config/sparc/sparc.h (INIT_EXPANDERS): In 32-bit mode, lower the
	alignment of 3 virtual registers to BITS_PER_WORD.

	* config/sparc/sparc.c (sparc_compute_frame_size): Simplify.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@255616 138bc75d-0d04-0410-961f-82ee72b054a4

5 files changed, 41 insertions, 18 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index c47696cd8a0..272bb7696f2 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,15 @@
+2017-12-13  Eric Botcazou  <ebotcazou@adacore.com>
+            Dominik Vogt  <vogt@linux.vnet.ibm.com>
+
+	PR middle-end/78468
+	* emit-rtl.c (init_emit): Remove ??? comment.
+	* explow.c (get_dynamic_stack_size): Take known alignment of stack
+	pointer + STACK_DYNAMIC_OFFSET into account in lieu of STACK_BOUNDARY.
+	* config/sparc/sparc.h (INIT_EXPANDERS): In 32-bit mode, lower the
+	alignment of 3 virtual registers to BITS_PER_WORD.
+
+	* config/sparc/sparc.c (sparc_compute_frame_size): Simplify.
+
 2017-12-13  Peter Bergner  <bergner@vnet.ibm.com>
 
 	* config/rs6000/ppc-auxv.h (PPC_FEATURE2_HTM_NO_SUSPEND): New define.
diff --git a/gcc/config/sparc/sparc.c b/gcc/config/sparc/sparc.c
index a8d363ce571..890bde9fc0a 100644
--- a/gcc/config/sparc/sparc.c
+++ b/gcc/config/sparc/sparc.c
@@ -5483,10 +5483,8 @@ sparc_compute_frame_size (HOST_WIDE_INT size, int leaf_function)
     frame_size = apparent_frame_size = 0;
   else
     {
-      /* We subtract TARGET_STARTING_FRAME_OFFSET, remember it's negative.  */
-      apparent_frame_size
-	= ROUND_UP (size - targetm.starting_frame_offset (), 8);
-      apparent_frame_size += n_global_fp_regs * 4;
+      /* Start from the apparent frame size.  */
+      apparent_frame_size = ROUND_UP (size, 8) + n_global_fp_regs * 4;
 
       /* We need to add the size of the outgoing argument area.  */
       frame_size = apparent_frame_size + ROUND_UP (args_size, 8);
diff --git a/gcc/config/sparc/sparc.h b/gcc/config/sparc/sparc.h
index a0b56126fd5..3d8e198b307 100644
--- a/gcc/config/sparc/sparc.h
+++ b/gcc/config/sparc/sparc.h
@@ -771,13 +771,29 @@ extern enum cmodel sparc_cmodel;
 /* The soft frame pointer does not have the stack bias applied.  */
 #define FRAME_POINTER_REGNUM 101
 
-/* Given the stack bias, the stack pointer isn't actually aligned.  */
 #define INIT_EXPANDERS							 \
   do {									 \
-    if (crtl->emit.regno_pointer_align && SPARC_STACK_BIAS)	 \
+    if (crtl->emit.regno_pointer_align)					 \
       {									 \
-	REGNO_POINTER_ALIGN (STACK_POINTER_REGNUM) = BITS_PER_UNIT;	 \
-	REGNO_POINTER_ALIGN (HARD_FRAME_POINTER_REGNUM) = BITS_PER_UNIT; \
+	/* The biased stack pointer is only aligned on BITS_PER_UNIT.  */\
+	if (SPARC_STACK_BIAS)						 \
+	  {								 \
+	    REGNO_POINTER_ALIGN (STACK_POINTER_REGNUM)			 \
+	      = BITS_PER_UNIT;	 					 \
+	    REGNO_POINTER_ALIGN (HARD_FRAME_POINTER_REGNUM)		 \
+	      = BITS_PER_UNIT;						 \
+	  }								 \
+									 \
+	/* In 32-bit mode, not everything is double-word aligned.  */	 \
+	if (TARGET_ARCH32)						 \
+	  {								 \
+	    REGNO_POINTER_ALIGN (VIRTUAL_INCOMING_ARGS_REGNUM)		 \
+	      = BITS_PER_WORD;						 \
+	    REGNO_POINTER_ALIGN (VIRTUAL_STACK_DYNAMIC_REGNUM)		 \
+	      = BITS_PER_WORD;						 \
+	    REGNO_POINTER_ALIGN (VIRTUAL_OUTGOING_ARGS_REGNUM)		 \
+	      = BITS_PER_WORD;						 \
+	  }								 \
       }									 \
   } while (0)
 
diff --git a/gcc/emit-rtl.c b/gcc/emit-rtl.c
index 42de598067f..5ab1fb79085 100644
--- a/gcc/emit-rtl.c
+++ b/gcc/emit-rtl.c
@@ -5764,8 +5764,6 @@ init_emit (void)
   REGNO_POINTER_ALIGN (HARD_FRAME_POINTER_REGNUM) = STACK_BOUNDARY;
   REGNO_POINTER_ALIGN (ARG_POINTER_REGNUM) = STACK_BOUNDARY;
 
-  /* ??? These are problematic (for example, 3 out of 4 are wrong on
-     32-bit SPARC and cannot be all fixed because of the ABI).  */
   REGNO_POINTER_ALIGN (VIRTUAL_INCOMING_ARGS_REGNUM) = STACK_BOUNDARY;
   REGNO_POINTER_ALIGN (VIRTUAL_STACK_VARS_REGNUM) = STACK_BOUNDARY;
   REGNO_POINTER_ALIGN (VIRTUAL_STACK_DYNAMIC_REGNUM) = STACK_BOUNDARY;
diff --git a/gcc/explow.c b/gcc/explow.c
index e2c8e459a43..696f06673eb 100644
--- a/gcc/explow.c
+++ b/gcc/explow.c
@@ -1206,7 +1206,6 @@ get_dynamic_stack_size (rtx *psize, unsigned size_align,
 			unsigned required_align,
 			HOST_WIDE_INT *pstack_usage_size)
 {
-  unsigned extra = 0;
   rtx size = *psize;
 
   /* Ensure the size is in the proper mode.  */
@@ -1242,16 +1241,16 @@ get_dynamic_stack_size (rtx *psize, unsigned size_align,
      example), so we must preventively align the value.  We leave space
      in SIZE for the hole that might result from the alignment operation.  */
 
-  /* Since the stack is presumed to be aligned before this allocation,
-     we only need to increase the size of the allocation if the required
-     alignment is more than the stack alignment.  */
-  if (required_align > STACK_BOUNDARY)
+  unsigned known_align = REGNO_POINTER_ALIGN (VIRTUAL_STACK_DYNAMIC_REGNUM);
+  if (known_align == 0)
+    known_align = BITS_PER_UNIT;
+  if (required_align > known_align)
     {
-      extra = (required_align - STACK_BOUNDARY) / BITS_PER_UNIT;
+      unsigned extra = (required_align - known_align) / BITS_PER_UNIT;
       size = plus_constant (Pmode, size, extra);
       size = force_operand (size, NULL_RTX);
-      if (size_align > STACK_BOUNDARY)
-	size_align = STACK_BOUNDARY;
+      if (size_align > known_align)
+	size_align = known_align;
 
       if (flag_stack_usage_info && pstack_usage_size)
 	*pstack_usage_size += extra;