From 3fbf0789202b30a67b12e1fb785c7130f098d665 Mon Sep 17 00:00:00 2001
From: Richard Sandiford <[email protected]>
Date: Tue, 12 Sep 2023 16:08:52 +0100
Subject: [PATCH] aarch64: Rename hard_fp_offset to bytes_above_hard_fp
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Similarly to the previous locals_offset patch, hard_fp_offset
was described as:

  /* Offset from the base of the frame (incomming SP) to the
     hard_frame_pointer.  This value is always a multiple of
     STACK_BOUNDARY.  */
  poly_int64 hard_fp_offset;

which again took an “upside-down” view: higher offsets meant lower
addresses.  This patch renames the field to bytes_above_hard_fp instead.

gcc/
	* config/aarch64/aarch64.h (aarch64_frame::hard_fp_offset): Rename
	to...
	(aarch64_frame::bytes_above_hard_fp): ...this.
	* config/aarch64/aarch64.cc (aarch64_layout_frame)
	(aarch64_expand_prologue): Update accordingly.
	(aarch64_initial_elimination_offset): Likewise.
---
 gcc/config/aarch64/aarch64.cc | 26 +++++++++++++-------------
 gcc/config/aarch64/aarch64.h  |  6 +++---
 2 files changed, 16 insertions(+), 16 deletions(-)

diff --git a/gcc/config/aarch64/aarch64.cc b/gcc/config/aarch64/aarch64.cc
index d4ec352ba98..3c4052740e7 100644
--- a/gcc/config/aarch64/aarch64.cc
+++ b/gcc/config/aarch64/aarch64.cc
@@ -8329,7 +8329,7 @@ aarch64_layout_frame (void)
 			   + get_frame_size (),
 			   STACK_BOUNDARY / BITS_PER_UNIT);
 
-  frame.hard_fp_offset
+  frame.bytes_above_hard_fp
     = saved_regs_and_above - frame.below_hard_fp_saved_regs_size;
 
   /* Both these values are already aligned.  */
@@ -8378,13 +8378,13 @@ aarch64_layout_frame (void)
   else if (frame.wb_pop_candidate1 != INVALID_REGNUM)
     max_push_offset = 256;
 
-  HOST_WIDE_INT const_size, const_below_saved_regs, const_fp_offset;
+  HOST_WIDE_INT const_size, const_below_saved_regs, const_above_fp;
   HOST_WIDE_INT const_saved_regs_size;
   if (known_eq (frame.saved_regs_size, 0))
     frame.initial_adjust = frame.frame_size;
   else if (frame.frame_size.is_constant (&const_size)
 	   && const_size < max_push_offset
-	   && known_eq (frame.hard_fp_offset, const_size))
+	   && known_eq (frame.bytes_above_hard_fp, const_size))
     {
       /* Simple, small frame with no data below the saved registers.
 
@@ -8401,8 +8401,8 @@ aarch64_layout_frame (void)
 	      case that it hardly seems worth the effort though.  */
 	   && (!saves_below_hard_fp_p || const_below_saved_regs == 0)
 	   && !(cfun->calls_alloca
-		&& frame.hard_fp_offset.is_constant (&const_fp_offset)
-		&& const_fp_offset < max_push_offset))
+		&& frame.bytes_above_hard_fp.is_constant (&const_above_fp)
+		&& const_above_fp < max_push_offset))
     {
       /* Frame with small area below the saved registers:
 
@@ -8420,12 +8420,12 @@ aarch64_layout_frame (void)
 	 sub sp, sp, hard_fp_offset + below_hard_fp_saved_regs_size
 	 save SVE registers relative to SP
 	 sub sp, sp, bytes_below_saved_regs  */
-      frame.initial_adjust = (frame.hard_fp_offset
+      frame.initial_adjust = (frame.bytes_above_hard_fp
 			      + frame.below_hard_fp_saved_regs_size);
       frame.final_adjust = frame.bytes_below_saved_regs;
     }
-  else if (frame.hard_fp_offset.is_constant (&const_fp_offset)
-	   && const_fp_offset < max_push_offset)
+  else if (frame.bytes_above_hard_fp.is_constant (&const_above_fp)
+	   && const_above_fp < max_push_offset)
     {
       /* Frame with large area below the saved registers, or with SVE saves,
 	 but with a small area above:
@@ -8435,7 +8435,7 @@ aarch64_layout_frame (void)
 	 [sub sp, sp, below_hard_fp_saved_regs_size]
 	 [save SVE registers relative to SP]
 	 sub sp, sp, bytes_below_saved_regs  */
-      frame.callee_adjust = const_fp_offset;
+      frame.callee_adjust = const_above_fp;
       frame.sve_callee_adjust = frame.below_hard_fp_saved_regs_size;
       frame.final_adjust = frame.bytes_below_saved_regs;
     }
@@ -8450,7 +8450,7 @@ aarch64_layout_frame (void)
 	 [sub sp, sp, below_hard_fp_saved_regs_size]
 	 [save SVE registers relative to SP]
 	 sub sp, sp, bytes_below_saved_regs  */
-      frame.initial_adjust = frame.hard_fp_offset;
+      frame.initial_adjust = frame.bytes_above_hard_fp;
       frame.sve_callee_adjust = frame.below_hard_fp_saved_regs_size;
       frame.final_adjust = frame.bytes_below_saved_regs;
     }
@@ -9754,7 +9754,7 @@ aarch64_expand_prologue (void)
     {
       /* The offset of the frame chain record (if any) from the current SP.  */
       poly_int64 chain_offset = (initial_adjust + callee_adjust
-				 - frame.hard_fp_offset);
+				 - frame.bytes_above_hard_fp);
       gcc_assert (known_ge (chain_offset, 0));
 
       if (callee_adjust == 0)
@@ -12575,10 +12575,10 @@ aarch64_initial_elimination_offset (unsigned from, unsigned to)
   if (to == HARD_FRAME_POINTER_REGNUM)
     {
       if (from == ARG_POINTER_REGNUM)
-	return frame.hard_fp_offset;
+	return frame.bytes_above_hard_fp;
 
       if (from == FRAME_POINTER_REGNUM)
-	return frame.hard_fp_offset - frame.bytes_above_locals;
+	return frame.bytes_above_hard_fp - frame.bytes_above_locals;
     }
 
   if (to == STACK_POINTER_REGNUM)
diff --git a/gcc/config/aarch64/aarch64.h b/gcc/config/aarch64/aarch64.h
index bf46e6124aa..dd1f403f939 100644
--- a/gcc/config/aarch64/aarch64.h
+++ b/gcc/config/aarch64/aarch64.h
@@ -890,10 +890,10 @@ struct GTY (()) aarch64_frame
      STACK_BOUNDARY.  */
   poly_int64 bytes_above_locals;
 
-  /* Offset from the base of the frame (incomming SP) to the
-     hard_frame_pointer.  This value is always a multiple of
+  /* The number of bytes between the hard_frame_pointer and the top of
+     the frame (the incomming SP).  This value is always a multiple of
      STACK_BOUNDARY.  */
-  poly_int64 hard_fp_offset;
+  poly_int64 bytes_above_hard_fp;
 
   /* The size of the frame.  This value is the offset from base of the
      frame (incomming SP) to the stack_pointer.  This value is always
-- 
2.37.3