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[committed] MIPS hazards at the end of a file

Oops.  I forgot about the alignment differences between traditional and
non-traditional MIPS targets when doing the recent 24k patch.  It turns
out that the extra alignment was causing bogus passes on mips*-linux-gnu,
and that the tests were still failing on mips*-elf* targets.

As I said in the previous message, the idea is that we should assume
the worst whenever we lose track of what the next instruction is.
This includes branch targets, section switches, and run-through
to the end of file.

It turns out that we don't actually handle the last case properly.
If a potential hazard comes at the end of a file, such as:

	mflo	$4

on targets without hi/lo interlocks, then we won't emit the required
nops.  However, if we follow it with a spurious section switch (a case
we do handle correctly) then everything is fine:

	mflo	$4
	.data

This seems to be a very long-standing bug that even affects the
old MIPS I tests.

Fixed with the patch below.  Tested on:

    mips64-elf mips64el-unknown-kfreebsd-gnu mips64-linux-gnu
    mips64octeon-linux-gnu mips64-unknown-kfreebsd-gnu
    mipsel-unknown-kfreebsd-gnu mipsisa32el-linux-gnu
    mipsisa64-elf mips-linux-gnu mips-sgi-irix6.5
    mips-unknown-kfreebsd-gnu mips-wrs-vxworks

and applied.

Richard


gas/
	* config/tc-mips.c (md_mips_end): Call mips_emit_delays.

gas/testsuite/
	* gas/mips/24k-triple-stores-9.d: Add -z to dump options and
	explicitly match one nop.
	* gas/mips/24k-triple-stores-10.d: Likewise.
	* gas/mips/24k-triple-stores-11.d: Likewise.
	* gas/mips/lifloat.d: Likewise.
	* gas/mips/trunc.d: Likewise 1 extra nop.
	* gas/mips/vr4111.d: Likewise 2 nops.

Index: gas/config/tc-mips.c
===================================================================
--- gas/config/tc-mips.c	2011-06-29 20:30:08.000000000 +0100
+++ gas/config/tc-mips.c	2011-06-29 21:25:16.000000000 +0100
@@ -2111,6 +2111,7 @@ md_begin (void)
 void
 md_mips_end (void)
 {
+  mips_emit_delays ();
   if (! ECOFF_DEBUGGING)
     md_obj_end ();
 }
Index: gas/testsuite/gas/mips/24k-triple-stores-9.d
===================================================================
--- gas/testsuite/gas/mips/24k-triple-stores-9.d	2011-06-29 20:04:35.000000000 +0100
+++ gas/testsuite/gas/mips/24k-triple-stores-9.d	2011-06-29 20:36:48.000000000 +0100
@@ -1,4 +1,4 @@
-#objdump: -dr
+#objdump: -drz
 #as: -mfix-24k -32
 #name: 24K: Triple store (Intervening data #1)
 
@@ -12,4 +12,5 @@ Disassembly of section .text:
    8:	a1030008 	sb	v1,8\(t0\)
    c:	00000000 	nop
   10:	a1040010 	sb	a0,16\(t0\)
-	\.\.\.
+  14:	00000000 	nop
+#pass
Index: gas/testsuite/gas/mips/24k-triple-stores-10.d
===================================================================
--- gas/testsuite/gas/mips/24k-triple-stores-10.d	2011-06-29 20:04:35.000000000 +0100
+++ gas/testsuite/gas/mips/24k-triple-stores-10.d	2011-06-29 20:34:18.000000000 +0100
@@ -1,4 +1,4 @@
-#objdump: -dr
+#objdump: -dr -z
 #as: -mfix-24k -32
 #name: 24K: Triple Store (Intervening data #2)
 
@@ -10,4 +10,5 @@ Disassembly of section .text:
    4:	a1030008 	sb	v1,8\(t0\)
    8:	00000000 	nop
    c:	a1040010 	sb	a0,16\(t0\)
-	\.\.\.
+  10:	00000000 	nop
+#pass
Index: gas/testsuite/gas/mips/24k-triple-stores-11.d
===================================================================
--- gas/testsuite/gas/mips/24k-triple-stores-11.d	2011-06-29 20:32:32.000000000 +0100
+++ gas/testsuite/gas/mips/24k-triple-stores-11.d	2011-06-29 20:36:45.000000000 +0100
@@ -1,4 +1,4 @@
-#objdump: -d
+#objdump: -dz
 #as: -mfix-24k -32
 #name: 24K: Triple Store (gprel relocs)
 
@@ -14,4 +14,5 @@ Disassembly of section .text:
   14:	af830000 	sw	v1,0\(gp\)
   18:	00000000 	nop
   1c:	af840000 	sw	a0,0\(gp\)
-
+  20:	00000000 	nop
+#pass
Index: gas/testsuite/gas/mips/lifloat.d
===================================================================
--- gas/testsuite/gas/mips/lifloat.d	2011-06-29 20:37:19.000000000 +0100
+++ gas/testsuite/gas/mips/lifloat.d	2011-06-29 20:37:36.000000000 +0100
@@ -1,4 +1,4 @@
-#objdump: -dr --prefix-addresses -mmips:3000
+#objdump: -drz --prefix-addresses -mmips:3000
 #name: MIPS lifloat
 #as: -32 -mips1
 
@@ -21,3 +21,5 @@ Disassembly of section .text:
 0+0018 <[^>]*> ori	a0,a0,0xcd36
 0+001c <[^>]*> lwc1	\$f4,[-0-9]+\(gp\)
 [ 	]*1c: [A-Z0-9_]*LITERAL[A-Z0-9_]*	.lit4.*
+0+0020 <[^>]*> nop
+#pass
Index: gas/testsuite/gas/mips/trunc.d
===================================================================
--- gas/testsuite/gas/mips/trunc.d	2011-06-29 20:37:51.000000000 +0100
+++ gas/testsuite/gas/mips/trunc.d	2011-06-29 20:38:43.000000000 +0100
@@ -1,4 +1,4 @@
-#objdump: -dr --prefix-addresses -mmips:3000
+#objdump: -drz --prefix-addresses -mmips:3000
 #name: MIPS trunc
 #as: -32 -mips1 -mtune=r3000
 
@@ -27,3 +27,5 @@ Disassembly of section .text:
 0+0044 <[^>]*> cvt.w.s	\$f4,\$f6
 0+0048 <[^>]*> ctc1	a0,\$31
 0+004c <[^>]*> nop
+0+0050 <[^>]*> nop
+#pass
Index: gas/testsuite/gas/mips/vr4111.d
===================================================================
--- gas/testsuite/gas/mips/vr4111.d	2011-06-29 20:39:00.000000000 +0100
+++ gas/testsuite/gas/mips/vr4111.d	2011-06-29 20:42:10.000000000 +0100
@@ -1,4 +1,4 @@
-#objdump: -dr
+#objdump: -drz
 #name: MIPS VR4111
 #as: -march=vr4111
 
@@ -7,5 +7,9 @@
 Disassembly of section \.text:
 0+000 <\.text>:
  + 0:	00850029 	dmadd16	a0,a1
-	\.\.\.
+ + 4:	00000000 	nop
+ + 8:	00000000 	nop
  + c:	00a60028 	madd16	a1,a2
+ +10:	00000000 	nop
+ +14:	00000000 	nop
+#pass
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