ARM pc-relative loads

[Paul Brook <paul at codesourcery dot com>]

The patch below fixes a failure observed building a hacked-up variant of the 
linux kernel.

The assembler is failing to resolve a pc-relative Thumb load from a global 
symbol in the same section.  My first guess was that this is a feature - 
symbol preemption requires the address be resolved at dynamic link time.  
However the offset range of pc-relative load instructions is sufficiently 
small that I don't believe that symbol preemption would ever actually succeed 
in practice.

We already resolve the equivalent ARM relocation. Arguably this is a bug. 
However there is code that relies on this behavior. Given the uselessness of 
exporting these relocations I've chosen to go for consistency with ARM LDR, 
and resolve the relocation.  Further investigation revealed a handful of other 
load instructions that also need to be handled.

Tested on arm-none-eabi
Applied to CVS head

Paul

2011-05-31  Paul Brook  <paul@codesourcery.com>

	gas/
	* config/tc-arm.c (arm_force_relocation): Resolve all pc-relative
	loads.

	gas/testsuite/
	* gas/arm/ldr-global.d: New test.
	* gas/arm/ldr-global.s: New test.

diff --git a/gas/config/tc-arm.c b/gas/config/tc-arm.c
index a9839cd..5430367 100644
--- a/gas/config/tc-arm.c
+++ b/gas/config/tc-arm.c
@@ -22769,6 +22769,8 @@ static const struct arm_cpu_option_table arm_cpus[] =
   {"cortex-r4",		ARM_ARCH_V7R,	 FPU_NONE,	  "Cortex-R4"},
   {"cortex-r4f",	ARM_ARCH_V7R,	 FPU_ARCH_VFP_V3D16,
   							  "Cortex-R4F"},
+  {"cortex-r5",		ARM_ARCH_V7R_IDIV,
+					 FPU_NONE,	  "Cortex-R5"},
   {"cortex-m4",		ARM_ARCH_V7EM,	 FPU_NONE,	  "Cortex-M4"},
   {"cortex-m3",		ARM_ARCH_V7M,	 FPU_NONE,	  "Cortex-M3"},
   {"cortex-m1",		ARM_ARCH_V6SM,	 FPU_NONE,	  "Cortex-M1"},
@@ -22852,7 +22854,7 @@ struct arm_option_extension_value_table
 static const struct arm_option_extension_value_table arm_extensions[] =
 {
   {"idiv",	ARM_FEATURE (ARM_EXT_ADIV | ARM_EXT_DIV, 0),
-				   ARM_FEATURE (ARM_EXT_V7A, 0)},
+				   ARM_FEATURE (ARM_EXT_V7A | ARM_EXT_V7R, 0)},
   {"iwmmxt",	ARM_FEATURE (0, ARM_CEXT_IWMMXT),	ARM_ANY},
   {"iwmmxt2",	ARM_FEATURE (0, ARM_CEXT_IWMMXT2),	ARM_ANY},
   {"maverick",	ARM_FEATURE (0, ARM_CEXT_MAVERICK),	ARM_ANY},
diff --git a/gas/doc/c-arm.texi b/gas/doc/c-arm.texi
index a5a88ba..131f6ab 100644
--- a/gas/doc/c-arm.texi
+++ b/gas/doc/c-arm.texi
@@ -152,7 +152,7 @@ been added, again in ascending alphabetical order.  For example,
 
 
 The following extensions are currently supported:
-@code{idiv}, (Integer Divide Extensions for v7-A architecture),
+@code{idiv}, (Integer Divide Extensions for v7-A and v7-R architectures),
 @code{iwmmxt},
 @code{iwmmxt2},
 @code{maverick},
diff --git a/gas/testsuite/gas/arm/arm-idiv-bad.d b/gas/testsuite/gas/arm/arm-idiv-bad.d
new file mode 100644
index 0000000..c3d7394
--- /dev/null
+++ b/gas/testsuite/gas/arm/arm-idiv-bad.d
@@ -0,0 +1,4 @@
+#name: Invalid V7 ARM DIV instructions
+#as: -march=armv7-a
+#error-output: arm-idiv-bad.l
+
diff --git a/gas/testsuite/gas/arm/arm-idiv-bad.l b/gas/testsuite/gas/arm/arm-idiv-bad.l
new file mode 100644
index 0000000..6662cc7
--- /dev/null
+++ b/gas/testsuite/gas/arm/arm-idiv-bad.l
@@ -0,0 +1,2 @@
+[^:]*: Assembler messages:
+[^:]*:4: Error: selected processor does not support ARM mode `sdiv r0,r0,r0'
diff --git a/gas/testsuite/gas/arm/arm-idiv-bad.s b/gas/testsuite/gas/arm/arm-idiv-bad.s
new file mode 100644
index 0000000..45e846e
--- /dev/null
+++ b/gas/testsuite/gas/arm/arm-idiv-bad.s
@@ -0,0 +1,4 @@
+	.text
+	.arm
+label:
+	sdiv	r0, r0, r0
diff --git a/gas/testsuite/gas/arm/arm-idiv.d b/gas/testsuite/gas/arm/arm-idiv.d
new file mode 100644
index 0000000..a886d02
--- /dev/null
+++ b/gas/testsuite/gas/arm/arm-idiv.d
@@ -0,0 +1,9 @@
+#name: ARM Integer division instructions
+#objdump: -dr --prefix-addresses --show-raw-insn
+
+.*: +file format .*arm.*
+
+Disassembly of section .text:
+0+000 <[^>]*> e735f819 	udiv	r5, r9, r8
+0+004 <[^>]*> e739f715 	udiv	r9, r5, r7
+0+008 <[^>]*> e710f010 	sdiv	r0, r0, r0
diff --git a/gas/testsuite/gas/arm/arm-idiv.s b/gas/testsuite/gas/arm/arm-idiv.s
new file mode 100644
index 0000000..626a67d
--- /dev/null
+++ b/gas/testsuite/gas/arm/arm-idiv.s
@@ -0,0 +1,8 @@
+.arch armv7-a
+.arch_extension idiv
+.arm
+udiv r5, r9, r8
+.cpu cortex-a15
+udiv r9, r5, r7
+.cpu cortex-r5
+sdiv r0, r0, r0
diff --git a/include/opcode/arm.h b/include/opcode/arm.h
index 297ca63..86e3d67 100644
--- a/include/opcode/arm.h
+++ b/include/opcode/arm.h
@@ -229,6 +229,8 @@
 			ARM_FEATURE (ARM_AEXT_V7A | ARM_EXT_MP | ARM_EXT_SEC \
 				     | ARM_EXT_DIV | ARM_EXT_ADIV \
 				     | ARM_EXT_VIRT, 0)
+/* v7-r+idiv.  */
+#define ARM_ARCH_V7R_IDIV	ARM_FEATURE (ARM_AEXT_V7R | ARM_EXT_ADIV, 0)
 /* Features that are present in v6M and v6S-M but not other v6 cores.  */
 #define ARM_ARCH_V6M_ONLY ARM_FEATURE (ARM_AEXT_V6M_ONLY, 0)