[PATCH] [ARM] Post-indexed addressing for NEON memory access

[Charles Baylis]

This patch adds support for post-indexed addressing for NEON structure
memory accesses.

For example VLD1.8 {d0}, [r0], r1


Bootstrapped and checked on arm-unknown-gnueabihf using Qemu.

Ok for trunk?


gcc/Changelog:

2014-06-02  Charles Baylis  <charles.bay...@linaro.org>

        * config/arm/arm.c (neon_vector_mem_operand): Allow register
        POST_MODIFY for neon loads and stores.
        (arm_print_operand): Output post-index register for neon loads and
        stores.

From a8e0bdbceab00d5e5b655611965d3975ba74365c Mon Sep 17 00:00:00 2001
From: Charles Baylis <charles.bay...@linaro.org>
Date: Tue, 6 May 2014 15:23:46 +0100
Subject: [PATCH] post-indexed addressing for vld/vst

2014-05-09  Charles Baylis  <charles.bay...@linaro.org>

	* config/arm/arm.c (neon_vector_mem_operand): Allow register
	POST_MODIFY for neon loads and stores.
	(arm_print_operand): Output post-index register for neon loads and
	stores.
---
 gcc/config/arm/arm.c | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
index 1117bd4..6ab02ef 100644
--- a/gcc/config/arm/arm.c
+++ b/gcc/config/arm/arm.c
@@ -12786,7 +12786,11 @@ neon_vector_mem_operand (rtx op, int type, bool strict)
       || (type == 0 && GET_CODE (ind) == PRE_DEC))
     return arm_address_register_rtx_p (XEXP (ind, 0), 0);
 
-  /* FIXME: vld1 allows register post-modify.  */
+  /* Allow post-increment by register for VLDn */
+  if (type == 2 && GET_CODE (ind) == POST_MODIFY
+      && GET_CODE (XEXP (ind, 1)) == PLUS
+      && REG_P (XEXP (XEXP (ind, 1), 1)))
+     return true;
 
   /* Match:
      (plus (reg)
@@ -21816,6 +21820,7 @@ arm_print_operand (FILE *stream, rtx x, int code)
       {
 	rtx addr;
 	bool postinc = FALSE;
+	rtx postinc_reg = NULL;
 	unsigned align, memsize, align_bits;
 
 	gcc_assert (MEM_P (x));
@@ -21825,6 +21830,11 @@ arm_print_operand (FILE *stream, rtx x, int code)
 	    postinc = 1;
 	    addr = XEXP (addr, 0);
 	  }
+	if (GET_CODE (addr) == POST_MODIFY)
+	  {
+	    postinc_reg = XEXP( XEXP (addr, 1), 1);
+	    addr = XEXP (addr, 0);
+	  }
 	asm_fprintf (stream, "[%r", REGNO (addr));
 
 	/* We know the alignment of this access, so we can emit a hint in the
@@ -21850,6 +21860,8 @@ arm_print_operand (FILE *stream, rtx x, int code)
 
 	if (postinc)
 	  fputs("!", stream);
+	if (postinc_reg)
+	  asm_fprintf (stream, ", %r", REGNO (postinc_reg));
       }
       return;
 
-- 
1.9.1