[binutils-gdb] MIPS/GAS: Clear the ASE_MIPS16E2_MT flag for recalculation

[Maciej W.Rozycki <macro at sourceware dot org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=92cebb3dbea282bbf7357ed2f3f03bc92fee8c7b

commit 92cebb3dbea282bbf7357ed2f3f03bc92fee8c7b
Author: Maciej W. Rozycki <macro@imgtec.com>
Date:   Fri Jun 30 00:55:07 2017 +0100

    MIPS/GAS: Clear the ASE_MIPS16E2_MT flag for recalculation
    
    Correct a commit 25499ac7ee92 ("MIPS16e2: Add MIPS16e2 ASE support") GAS
    bug with the handling of the ASE_MIPS16E2_MT combination ASE flag, which
    is not correctly calculated as `.set nomips16e2' and `.set nomt'
    pseudo-ops are processed.  This leads to code like:
    
    $ cat foo.s
    	.set	nomt
    	evpe
    	.align	4, 0
    $ cat bar.s
    	.set	nomips16e2
    	dvpe
    	.align	4, 0
    $
    
    to successfully assemble where it should not:
    
    $ as -32 -mips32r3 -mmt -mips16 -mmips16e2 -o foo.o foo.s
    $ as -32 -mips32r3 -mmt -mips16 -mmips16e2 -o bar.o bar.s
    $ objdump -m mips:16 -d foo.o
    
    foo.o:     file format elf32-tradbigmips
    
    Disassembly of section .text:
    
    00000000 <.text>:
       0:	f027 6700 	evpe
    	...
    
    bar.o:     file format elf32-tradbigmips
    
    Disassembly of section .text:
    
    00000000 <.text>:
       0:	f026 6700 	dvpe
    	...
    $
    
    This happens because ASE_MIPS16E2_MT once set in `mips_set_ase' is never
    cleared.  Fix the problem by clearing it there before it is calculated
    based on the ASE_MT and ASE_MIPS16E2 flags, making assembly fail as
    expected:
    
    $ as -32 -mips32r3 -mmt -mips16 -mmips16e2 -o foo.o foo.s
    foo.s: Assembler messages:
    foo.s:2: Error: opcode not supported on this processor: mips32r3 (mips32r3) `evpe'
    $ as -32 -mips32r3 -mmt -mips16 -mmips16e2 -o bar.o bar.s
    bar.s: Assembler messages:
    bar.s:2: Error: opcode not supported on this processor: mips32r3 (mips32r3) `dvpe'
    $
    
    	gas/
    	* config/tc-mips.c (mips_set_ase): Clear the ASE_MIPS16E2_MT
    	flag before recalculating.
    	* testsuite/gas/mips/mips16e2-mt-err.d: New test.
    	* testsuite/gas/mips/mips16e2-mt-err.l: New stderr output.
    	* testsuite/gas/mips/mips16e2-mt-err.s: New test source.
    	* testsuite/gas/mips/mips.exp: Run the new test.

Diff:
---
 gas/ChangeLog                            |  9 +++++++++
 gas/config/tc-mips.c                     |  5 +++++
 gas/testsuite/gas/mips/mips.exp          |  1 +
 gas/testsuite/gas/mips/mips16e2-mt-err.d |  3 +++
 gas/testsuite/gas/mips/mips16e2-mt-err.l |  3 +++
 gas/testsuite/gas/mips/mips16e2-mt-err.s | 14 ++++++++++++++
 6 files changed, 35 insertions(+)

diff --git a/gas/ChangeLog b/gas/ChangeLog
index 92d1f86..43a7528 100644
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,3 +1,12 @@
+2017-06-29  Maciej W. Rozycki  <macro@imgtec.com>
+
+	* config/tc-mips.c (mips_set_ase): Clear the ASE_MIPS16E2_MT
+	flag before recalculating.
+	* testsuite/gas/mips/mips16e2-mt-err.d: New test.
+	* testsuite/gas/mips/mips16e2-mt-err.l: New stderr output.
+	* testsuite/gas/mips/mips16e2-mt-err.s: New test source.
+	* testsuite/gas/mips/mips.exp: Run the new test.
+
 2017-06-28  Tamar Christina  <tamar.christina@arm.com>
 
 	* config/tc-aarch64.c (aarch64_reg_parse_32_64): Accept 4B.
diff --git a/gas/config/tc-mips.c b/gas/config/tc-mips.c
index d7a1ff3..d06143a 100644
--- a/gas/config/tc-mips.c
+++ b/gas/config/tc-mips.c
@@ -2130,6 +2130,11 @@ mips_set_ase (const struct mips_ase *ase, struct mips_set_options *opts,
 
   mask = mips_ase_mask (ase->flags);
   opts->ase &= ~mask;
+
+  /* Clear combination ASE flags, which need to be recalculated based on
+     updated regular ASE settings.  */
+  opts->ase &= ~ASE_MIPS16E2_MT;
+
   if (enabled_p)
     opts->ase |= ase->flags;
 
diff --git a/gas/testsuite/gas/mips/mips.exp b/gas/testsuite/gas/mips/mips.exp
index 4d327f5..26d29e4 100644
--- a/gas/testsuite/gas/mips/mips.exp
+++ b/gas/testsuite/gas/mips/mips.exp
@@ -1403,6 +1403,7 @@ if { [istarget mips*-*-vxworks*] } {
 
     run_dump_test "mips16e-jrc"
     run_dump_test "mips16e2-lui"
+    run_dump_test "mips16e2-mt-err"
     run_dump_test "mips16e2-copy"
     run_dump_test "mips16e2-copy-err"
 
diff --git a/gas/testsuite/gas/mips/mips16e2-mt-err.d b/gas/testsuite/gas/mips/mips16e2-mt-err.d
new file mode 100644
index 0000000..4dc0e99
--- /dev/null
+++ b/gas/testsuite/gas/mips/mips16e2-mt-err.d
@@ -0,0 +1,3 @@
+#name: MIPS16e2 MT ASE instruction errors
+#as: -32 -mips16 -mips32r2 -mmips16e2 -mmt
+#error-output: mips16e2-mt-err.l
diff --git a/gas/testsuite/gas/mips/mips16e2-mt-err.l b/gas/testsuite/gas/mips/mips16e2-mt-err.l
new file mode 100644
index 0000000..d9eb9b3
--- /dev/null
+++ b/gas/testsuite/gas/mips/mips16e2-mt-err.l
@@ -0,0 +1,3 @@
+.*: Assembler messages:
+.*:8: Error: opcode not supported on this processor: mips32r2 \(mips32r2\) `dvpe'
+.*:12: Error: opcode not supported on this processor: mips32r2 \(mips32r2\) `dvpe'
diff --git a/gas/testsuite/gas/mips/mips16e2-mt-err.s b/gas/testsuite/gas/mips/mips16e2-mt-err.s
new file mode 100644
index 0000000..78b43f4
--- /dev/null
+++ b/gas/testsuite/gas/mips/mips16e2-mt-err.s
@@ -0,0 +1,14 @@
+# Verify that switching off either `mips16e2' or `mt' causes an assembly
+# error with a MIPS16e2 MT ASE instruction, which requires both at a time.
+
+	.text
+foo:
+	evpe
+	.set	nomips16e2
+	dvpe
+	.set	mips16e2
+	evpe
+	.set	nomt
+	dvpe
+	.set	mt
+	evpe