patches/gcc/3.4.6/160-arm-ldm-peephole2.patch
author "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
Wed Dec 30 15:36:22 2009 +0100 (2009-12-30)
changeset 1669 61edd9d19e3c
parent 746 b150d6f590fc
permissions -rw-r--r--
scripts/functions: add aria2, a powerfull downloader

aria2 is a powerfull downloader that is capable of chunking and
parallel retrieval.

Due to li;itations in crosstool-NG retrieval facilities, it's not possible
to take fully advantage of aria2. It might happen that, in the future,
those limitations get lifted away, so we can take use features such as
parallel downloading from more than one server at the same time. For now,
it should still speed up downloads thanks to parallel downloading of chunks.
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diff -durN gcc-3.4.6.orig/gcc/config/arm/arm.c gcc-3.4.6/gcc/config/arm/arm.c
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--- gcc-3.4.6.orig/gcc/config/arm/arm.c	2007-08-15 22:57:51.000000000 +0200
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+++ gcc-3.4.6/gcc/config/arm/arm.c	2007-08-15 22:57:51.000000000 +0200
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@@ -4572,6 +4572,10 @@
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 int
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 adjacent_mem_locations (rtx a, rtx b)
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 {
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+  /* We don't guarantee to preserve the order of these memory refs.  */
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+  if (volatile_refs_p (a) || volatile_refs_p (b))
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+    return 0;
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+
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   if ((GET_CODE (XEXP (a, 0)) == REG
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        || (GET_CODE (XEXP (a, 0)) == PLUS
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 	   && GET_CODE (XEXP (XEXP (a, 0), 1)) == CONST_INT))
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@@ -4611,6 +4615,17 @@
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 	return 0;
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       val_diff = val1 - val0;
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+
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+      if (arm_ld_sched)
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+	{
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+	  /* If the target has load delay slots, then there's no benefit
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+	     to using an ldm instruction unless the offset is zero and
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+	     we are optimizing for size.  */
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+	  return (optimize_size && (REGNO (reg0) == REGNO (reg1))
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+		  && (val0 == 0 || val1 == 0 || val0 == 4 || val1 == 4)
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+		  && (val_diff == 4 || val_diff == -4));
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+	}
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+
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       return ((REGNO (reg0) == REGNO (reg1))
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 	      && (val_diff == 4 || val_diff == -4));
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     }