[GAS,ARM] Invalid LDR immediate transformation

Message ID CAKdteOazvmgHUt30vnp+5+PDs3jcyakCigHRKYbp6LUo=NSVEg@mail.gmail.com
State New
Headers show

Commit Message

Christophe Lyon Nov. 24, 2015, 9:27 p.m.
On 24 November 2015 at 16:46, Nick Clifton <nickc@redhat.com> wrote:
> Hi Christophe,

>

>> I have attached a patch, tested on an x86_64 host in arm-none-eabi

>> arm-linux-eabi arm-nacl, no regression.

>

>

> This patch is approved for the mainline.

>


I've commit it on Christophe's behalf.
It needed a small adjustment in the testcase after a recent fix from Matthew
in the same area.

I've attached what I have committed.
I hope I did it right (commit message), since it's my first commit in binutils
since we switched to git :-)


> It probably should go into the 2.26 branch as well, but please check with

> Tristan first.

>

Since Matthew's patch is in the 2.26 branch too, we need the updated
testcase if this patch is OK for 2.26. Tristan?

Thanks,

Christophe.

> Cheers

>   Nick

>

>

Patch

commit 2c32be708da9011b3ce7404f2be43b17ab1eddd4
Author: Christophe Monat <christophe.monat@st.com>
Date:   Tue Nov 24 22:17:54 2015 +0100

    [GAS, ARM] Invalid LDR immediate transformation
    
    2015-11-24  Christophe Monat <christophe.monat@st.com>
    
    	* config/tc-arm.c (move_or_literal_pool): Do not transform ldr
    	ri,=imm into movs when ri is a high register in T1.
    
    2015-11-24  Christophe Monat <christophe.monat@st.com>
    
    	* gas/arm/thumb2_ldr_immediate_armv6t2.s: Added high register
    	tests.
    	* gas/arm/thumb2_ldr_immediate_armv6t2.d: Accounted for new test
    	cases.
    	* gas/arm/thumb2_ldr_immediate_highregs_armv6t2.s: New.
    	* gas/arm/thumb2_ldr_immediate_highregs_armv6t2.d: New.

diff --git a/gas/ChangeLog b/gas/ChangeLog
index bec87cf..1077066 100644
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,3 +1,8 @@ 
+2015-11-24  Christophe Monat <christophe.monat@st.com>
+
+	* config/tc-arm.c (move_or_literal_pool): Do not transform ldr
+	ri,=imm into movs when ri is a high register in T1.
+
 2015-11-20  Nick Clifton  <nickc@redhat.com>
 
 	* po/fr.po: Updated French translation.
diff --git a/gas/config/tc-arm.c b/gas/config/tc-arm.c
index 23c506d..8ea1e8d 100644
--- a/gas/config/tc-arm.c
+++ b/gas/config/tc-arm.c
@@ -7839,7 +7839,8 @@  move_or_literal_pool (int i, enum lit_type t, bfd_boolean mode_3)
 	{
 	  if (thumb_p)
 	    {
-	      if ((v & ~0xFF) == 0)
+	      /* This can be encoded only for a low register.  */
+	      if ((v & ~0xFF) == 0 && (inst.operands[i].reg < 8))
 		{
 		  /* This can be done with a mov(1) instruction.  */
 		  inst.instruction = T_OPCODE_MOV_I8 | (inst.operands[i].reg << 8);
diff --git a/gas/testsuite/ChangeLog b/gas/testsuite/ChangeLog
index a38fc25..aae4691 100644
--- a/gas/testsuite/ChangeLog
+++ b/gas/testsuite/ChangeLog
@@ -1,3 +1,12 @@ 
+2015-11-24  Christophe Monat <christophe.monat@st.com>
+
+	* gas/arm/thumb2_ldr_immediate_armv6t2.s: Added high register
+	tests.
+	* gas/arm/thumb2_ldr_immediate_armv6t2.d: Accounted for new test
+	cases.
+	* gas/arm/thumb2_ldr_immediate_highregs_armv6t2.s: New.
+	* gas/arm/thumb2_ldr_immediate_highregs_armv6t2.d: New.
+
 2015-11-24  Matthew Wahab  <matthew.wahab@arm.com>
 
 	* gas/arm/armv7e-m+fpv5-d16.d: Skip test for *-*-pe, *-wince-* and
diff --git a/gas/testsuite/gas/arm/thumb2_ldr_immediate_armv6t2.d b/gas/testsuite/gas/arm/thumb2_ldr_immediate_armv6t2.d
index 6897bcd..09c46a8 100644
--- a/gas/testsuite/gas/arm/thumb2_ldr_immediate_armv6t2.d
+++ b/gas/testsuite/gas/arm/thumb2_ldr_immediate_armv6t2.d
@@ -1,4 +1,4 @@ 
-# name: Ldr immediate on armv6
+# name: Ldr immediate on armv6t2
 # as: -march=armv6t2
 # objdump: -dr --prefix-addresses --show-raw-insn
 #skip: *-*-pe *-wince-* *-*-coff
@@ -10,7 +10,13 @@  Disassembly of section .text:
 0[0-9a-f]+ <[^>]+> f04f 2163 	mov.w	r1, #1660969728	.*
 0[0-9a-f]+ <[^>]+> f04f 1151 	mov.w	r1, #5308497	.*
 0[0-9a-f]+ <[^>]+> f44f 228e 	mov.w	r2, #290816	.*
-0[0-9a-f]+ <[^>]+> 4a01      	ldr	r2, \[pc, #4\]	.*
+0[0-9a-f]+ <[^>]+> 4a07      	ldr	r2, \[pc, #28\]	.*
 0[0-9a-f]+ <[^>]+> f241 32f1 	movw	r2, #5105	.*
+0[0-9a-f]+ <[^>]+> f04f 3872 	mov.w	r8, #1920103026	.*
+0[0-9a-f]+ <[^>]+> f04f 2863 	mov.w	r8, #1660969728	.*
+0[0-9a-f]+ <[^>]+> f04f 1851 	mov.w	r8, #5308497	.*
+0[0-9a-f]+ <[^>]+> f44f 298e 	mov.w	r9, #290816	.*
+0[0-9a-f]+ <[^>]+> f8df 9008 	ldr.w	r9, \[pc, #8\]	.*
+0[0-9a-f]+ <[^>]+> f241 39f1 	movw	r9, #5105	.*
 0[0-9a-f]+ <[^>]+> 0000      	.short	0x0000
 0[0-9a-f]+ <[^>]+> ff320000 	.word	0xff320000
diff --git a/gas/testsuite/gas/arm/thumb2_ldr_immediate_armv6t2.s b/gas/testsuite/gas/arm/thumb2_ldr_immediate_armv6t2.s
index 22a5014..4b94c91 100644
--- a/gas/testsuite/gas/arm/thumb2_ldr_immediate_armv6t2.s
+++ b/gas/testsuite/gas/arm/thumb2_ldr_immediate_armv6t2.s
@@ -9,4 +9,10 @@  thumb2_ldr:
 	ldr r2,=0x00047000
 	ldr r2,=0xFF320000
 	ldr r2,=0x000013F1
+	ldr r8,=0x72727272
+	ldr r8,=0x63006300
+	ldr r8,=0x00510051
+	ldr r9,=0x00047000
+	ldr r9,=0xFF320000
+	ldr r9,=0x000013F1
 	.pool
diff --git a/gas/testsuite/gas/arm/thumb2_ldr_immediate_highregs_armv6t2.d b/gas/testsuite/gas/arm/thumb2_ldr_immediate_highregs_armv6t2.d
new file mode 100644
index 0000000..55b5f17
--- /dev/null
+++ b/gas/testsuite/gas/arm/thumb2_ldr_immediate_highregs_armv6t2.d
@@ -0,0 +1,24 @@ 
+# name: Ldr small immediate high registers on armv6t2
+# as: -march=armv6t2
+# objdump: -dr --prefix-addresses --show-raw-insn
+# not-target: *-*-*coff *-*-pe *-*-wince *-*-*aout* *-*-netbsd *-*-riscix*
+
+.*: +file format .*arm.*
+
+Disassembly of section \.text:
+0[0-9a-f]+ <[^>]+> 2000[[:space:]]+movs[[:space:]]+r0, #0.*
+0[0-9a-f]+ <[^>]+> 2108[[:space:]]+movs[[:space:]]+r1, #8.*
+0[0-9a-f]+ <[^>]+> 2251[[:space:]]+movs[[:space:]]+r2, #81.*
+0[0-9a-f]+ <[^>]+> 231f[[:space:]]+movs[[:space:]]+r3, #31.*
+0[0-9a-f]+ <[^>]+> 242f[[:space:]]+movs[[:space:]]+r4, #47.*
+0[0-9a-f]+ <[^>]+> 253f[[:space:]]+movs[[:space:]]+r5, #63.*
+0[0-9a-f]+ <[^>]+> 2680[[:space:]]+movs[[:space:]]+r6, #128.*
+0[0-9a-f]+ <[^>]+> 27ff[[:space:]]+movs[[:space:]]+r7, #255.*
+0[0-9a-f]+ <[^>]+> f04f 0800[[:space:]]+mov\.w[[:space:]]+r8, #0.*
+0[0-9a-f]+ <[^>]+> f04f 0908[[:space:]]+mov\.w[[:space:]]+r9, #8.*
+0[0-9a-f]+ <[^>]+> f04f 0a51[[:space:]]+mov\.w[[:space:]]+sl, #81.*
+0[0-9a-f]+ <[^>]+> f04f 0b1f[[:space:]]+mov\.w[[:space:]]+fp, #31.*
+0[0-9a-f]+ <[^>]+> f04f 0c2f[[:space:]]+mov\.w[[:space:]]+ip, #47.*
+0[0-9a-f]+ <[^>]+> f04f 0d3f[[:space:]]+mov\.w[[:space:]]+sp, #63.*
+0[0-9a-f]+ <[^>]+> f04f 0e80[[:space:]]+mov\.w[[:space:]]+lr, #128.*
+0[0-9a-f]+ <[^>]+> f04f 0fff[[:space:]]+mov\.w[[:space:]]+pc, #255.*
diff --git a/gas/testsuite/gas/arm/thumb2_ldr_immediate_highregs_armv6t2.s b/gas/testsuite/gas/arm/thumb2_ldr_immediate_highregs_armv6t2.s
new file mode 100644
index 0000000..d225410
--- /dev/null
+++ b/gas/testsuite/gas/arm/thumb2_ldr_immediate_highregs_armv6t2.s
@@ -0,0 +1,24 @@ 
+	.thumb
+	.syntax unified
+	.thumb_func
+thumb2_ldr:
+	# These can be encoded into movs since constant is small
+	# And register can be encoded in 3 bits
+	ldr r0,=0x00
+	ldr r1,=0x08
+	ldr r2,=0x51
+	ldr r3,=0x1F
+	ldr r4,=0x2F
+	ldr r5,=0x3F
+	ldr r6,=0x80
+	ldr r7,=0xFF
+	# These shall be encoded into mov.w
+	# Since register cannot be encoded in 3 bits
+	ldr r8,=0x00
+	ldr r9,=0x08
+	ldr r10,=0x51
+	ldr r11,=0x1F
+	ldr r12,=0x2F
+	ldr r13,=0x3F
+	ldr r14,=0x80
+	ldr r15,=0xFF