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Thumb-2 assembler fixes, 1/5
- From: "Joseph S. Myers" <joseph at codesourcery dot com>
- To: binutils at sourceware dot org
- Cc: Mark Mitchell <mark at codesourcery dot com>
- Date: Thu, 29 Jan 2009 01:03:33 +0000 (UTC)
- Subject: Thumb-2 assembler fixes, 1/5
- References: <Pine.LNX.4.64.0901290100550.13294@digraph.polyomino.org.uk>
This patch fixes a problem where the Thumb-2 assembler was failing to
use 16-bit encodings for mul instructions when possible. Tested with
no regressions with cross to arm-none-eabi. OK to commit?
gas:
2009-01-29 Paul Brook <paul@codesourcery.com>
Mark Mitchell <mark@codesourcery.com>
* config/tc-arm.c (do_t_mul): In Thumb-2 mode, use 16-bit encoding
of MUL when possible.
gas/testsuite:
2009-01-29 Paul Brook <paul@codesourcery.com>
Mark Mitchell <mark@codesourcery.com>
* gas/arm/thumb2_mul.s: New file.
* gas/arm/thumb2_mul.d: Likewise.
* gas/arm/thumb2_mul-bad.s: Likewise.
* gas/arm/thumb2_mul-bad.d: Likewise.
* gas/arm/thumb2_mul-bad.l: Likewise.
* gas/arm/t16-bad.s: Add tests for"mul" with high registers.
* gas/arm/t16-bad.l: Update accordingly.
diff -rupN binutils.orig/gas/config/tc-arm.c binutils-1/gas/config/tc-arm.c
--- binutils.orig/gas/config/tc-arm.c 2009-01-26 14:36:42.000000000 +0000
+++ binutils-1/gas/config/tc-arm.c 2009-01-29 00:43:59.000000000 +0000
@@ -9879,24 +9879,35 @@ do_t_msr (void)
static void
do_t_mul (void)
{
+ bfd_boolean narrow;
+
if (!inst.operands[2].present)
inst.operands[2].reg = inst.operands[0].reg;
- /* There is no 32-bit MULS and no 16-bit MUL. */
- if (unified_syntax && inst.instruction == T_MNEM_mul)
+ if (unified_syntax)
{
- inst.instruction = THUMB_OP32 (inst.instruction);
- inst.instruction |= inst.operands[0].reg << 8;
- inst.instruction |= inst.operands[1].reg << 16;
- inst.instruction |= inst.operands[2].reg << 0;
+ if (inst.size_req == 4
+ || (inst.operands[0].reg != inst.operands[1].reg
+ && inst.operands[0].reg != inst.operands[2].reg)
+ || inst.operands[1].reg > 7
+ || inst.operands[2].reg > 7)
+ narrow = FALSE;
+ else if (inst.instruction == T_MNEM_muls)
+ narrow = (current_it_mask == 0);
+ else
+ narrow = (current_it_mask != 0);
}
else
{
- constraint (!unified_syntax
- && inst.instruction == T_MNEM_muls, BAD_THUMB32);
- constraint (inst.operands[0].reg > 7 || inst.operands[1].reg > 7,
+ constraint (inst.instruction == T_MNEM_muls, BAD_THUMB32);
+ constraint (inst.operands[1].reg > 7 || inst.operands[2].reg > 7,
BAD_HIREG);
+ narrow = TRUE;
+ }
+ if (narrow)
+ {
+ /* 16-bit MULS/Conditional MUL. */
inst.instruction = THUMB_OP16 (inst.instruction);
inst.instruction |= inst.operands[0].reg;
@@ -9907,6 +9918,16 @@ do_t_mul (void)
else
constraint (1, _("dest must overlap one source register"));
}
+ else
+ {
+ constraint(inst.instruction != T_MNEM_mul,
+ _("Thumb-2 MUL must not set flags"));
+ /* 32-bit MUL. */
+ inst.instruction = THUMB_OP32 (inst.instruction);
+ inst.instruction |= inst.operands[0].reg << 8;
+ inst.instruction |= inst.operands[1].reg << 16;
+ inst.instruction |= inst.operands[2].reg << 0;
+ }
}
static void
diff -rupN binutils.orig/gas/testsuite/gas/arm/t16-bad.l binutils-1/gas/testsuite/gas/arm/t16-bad.l
--- binutils.orig/gas/testsuite/gas/arm/t16-bad.l 2008-03-05 01:31:26.000000000 +0000
+++ binutils-1/gas/testsuite/gas/arm/t16-bad.l 2009-01-29 00:43:59.000000000 +0000
@@ -185,3 +185,6 @@
[^:]*:135: Error: Thumb does not support the 2-argument form of this instruction -- `cpsid ai,#5'
[^:]*:138: Error: Thumb does not support conditional execution
[^:]*:141: Error: cannot honor width suffix -- `add r0,r1'
+[^:]*:145: Error: lo register required -- `mul r0,r0,r8'
+[^:]*:146: Error: lo register required -- `mul r0,r8,r0'
+[^:]*:147: Error: dest must overlap one source register -- `mul r8,r0,r0'
diff -rupN binutils.orig/gas/testsuite/gas/arm/t16-bad.s binutils-1/gas/testsuite/gas/arm/t16-bad.s
--- binutils.orig/gas/testsuite/gas/arm/t16-bad.s 2008-03-05 01:31:26.000000000 +0000
+++ binutils-1/gas/testsuite/gas/arm/t16-bad.s 2009-01-29 00:43:59.000000000 +0000
@@ -140,3 +140,8 @@ l:
.syntax unified
add r0, r1
+ @ Multiply
+ .syntax divided
+ mul r0, r0, r8
+ mul r0, r8, r0
+ mul r8, r0, r0
diff -rupN binutils.orig/gas/testsuite/gas/arm/thumb2_mul-bad.d binutils-1/gas/testsuite/gas/arm/thumb2_mul-bad.d
--- binutils.orig/gas/testsuite/gas/arm/thumb2_mul-bad.d 1970-01-01 00:00:00.000000000 +0000
+++ binutils-1/gas/testsuite/gas/arm/thumb2_mul-bad.d 2009-01-29 00:43:59.000000000 +0000
@@ -0,0 +1,3 @@
+#name: Invalid Thumb-2 multiply instructions
+#as: -march=armv6kt2
+#error-output: thumb2_mul-bad.l
diff -rupN binutils.orig/gas/testsuite/gas/arm/thumb2_mul-bad.l binutils-1/gas/testsuite/gas/arm/thumb2_mul-bad.l
--- binutils.orig/gas/testsuite/gas/arm/thumb2_mul-bad.l 1970-01-01 00:00:00.000000000 +0000
+++ binutils-1/gas/testsuite/gas/arm/thumb2_mul-bad.l 2009-01-29 00:43:59.000000000 +0000
@@ -0,0 +1,8 @@
+[^:]*: Assembler messages:
+[^:]*:10: Error: cannot honor width suffix -- `muleq.n r0,r0,r8'
+[^:]*:12: Error: cannot honor width suffix -- `muleq.n r0,r1,r1'
+[^:]*:13: Error: cannot honor width suffix -- `muleq.n r0,r1,r2'
+[^:]*:15: Error: Thumb-2 MUL must not set flags -- `mulseq r0,r0,r1'
+[^:]*:17: Error: Thumb-2 MUL must not set flags -- `muls.w r0,r0,r1'
+[^:]*:19: Error: Thumb-2 MUL must not set flags -- `muls r0,r0,r8'
+[^:]*:20: Error: Thumb-2 MUL must not set flags -- `muls r0,r8,r0'
diff -rupN binutils.orig/gas/testsuite/gas/arm/thumb2_mul-bad.s binutils-1/gas/testsuite/gas/arm/thumb2_mul-bad.s
--- binutils.orig/gas/testsuite/gas/arm/thumb2_mul-bad.s 1970-01-01 00:00:00.000000000 +0000
+++ binutils-1/gas/testsuite/gas/arm/thumb2_mul-bad.s 2009-01-29 00:43:59.000000000 +0000
@@ -0,0 +1,20 @@
+ .syntax unified
+ .text
+ .align 2
+ .global thumb2_mul
+ .thumb
+ .thumb_func
+thumb2_mul:
+ itttt eq
+ # Cannot use 16-bit encoding because of use of high register.
+ muleq.n r0, r0, r8
+ # Cannot use 16-bit encoding because source does not match destination.
+ muleq.n r0, r1, r1
+ muleq.n r0, r1, r2
+ # There is no conditional "muls".
+ mulseq r0, r0, r1
+ # There is no 32-bit "muls".
+ muls.w r0, r0, r1
+ # Cannot use high registers with "muls".
+ muls r0, r0, r8
+ muls r0, r8, r0
diff -rupN binutils.orig/gas/testsuite/gas/arm/thumb2_mul.d binutils-1/gas/testsuite/gas/arm/thumb2_mul.d
--- binutils.orig/gas/testsuite/gas/arm/thumb2_mul.d 1970-01-01 00:00:00.000000000 +0000
+++ binutils-1/gas/testsuite/gas/arm/thumb2_mul.d 2009-01-29 00:43:59.000000000 +0000
@@ -0,0 +1,19 @@
+# as: -march=armv6kt2
+# objdump: -dr --prefix-addresses --show-raw-insn
+
+.*: +file format .*arm.*
+
+Disassembly of section .text:
+0+000 <[^>]+> bf04 itt eq
+0+002 <[^>]+> 4348 muleq r0, r1
+0+004 <[^>]+> 4348 muleq r0, r1
+0+006 <[^>]+> bf02 ittt eq
+0+008 <[^>]+> fb00 f008 muleq.w r0, r0, r8
+0+00c <[^>]+> fb08 f000 muleq.w r0, r8, r0
+0+010 <[^>]+> fb00 f808 muleq.w r8, r0, r8
+0+014 <[^>]+> bf04 itt eq
+0+016 <[^>]+> fb01 f001 muleq.w r0, r1, r1
+0+01a <[^>]+> fb01 f002 muleq.w r0, r1, r2
+0+01e <[^>]+> bf04 itt eq
+0+020 <[^>]+> fb01 f000 muleq.w r0, r1, r0
+0+024 <[^>]+> fb00 f001 muleq.w r0, r0, r1
diff -rupN binutils.orig/gas/testsuite/gas/arm/thumb2_mul.s binutils-1/gas/testsuite/gas/arm/thumb2_mul.s
--- binutils.orig/gas/testsuite/gas/arm/thumb2_mul.s 1970-01-01 00:00:00.000000000 +0000
+++ binutils-1/gas/testsuite/gas/arm/thumb2_mul.s 2009-01-29 00:43:59.000000000 +0000
@@ -0,0 +1,29 @@
+ .syntax unified
+ .text
+ .align 2
+ .global thumb2_mul
+ .thumb
+ .thumb_func
+thumb2_mul:
+ # These can use the 16-bit encoding.
+ itt eq
+ muleq r0, r1, r0
+ muleq r0, r0, r1
+ # These must use the 32-bit encoding because they involve
+ # high registers.
+ ittt eq
+ muleq r0, r0, r8
+ muleq r0, r8, r0
+ muleq r8, r0, r8
+ # These must use the 32-bit encoding because the source and
+ # destination do not match.
+ itt eq
+ muleq r0, r1, r1
+ muleq r0, r1, r2
+ # These must use the 32-bit encoding because of the explicit
+ # suffix.
+ itt eq
+ muleq.w r0, r1, r0
+ muleq.w r0, r0, r1
+
+
--
Joseph S. Myers
joseph@codesourcery.com