[arm] Check for neon and condition in vcvt.f16.f32

VCVT between f16 and f32 is an Advanced SIMD instruction.
Not all the VCVT alternatives need neon, hence the check for neon is in
the encode function.

The check on neon for VCVT.f16.f32 (and vice versa) is missing.

vshcmd: > echo 'vcvt.f16.f32 d1, q1' | gas/as-new -mfpu=vfpxd -march=armv8.5-a -
testdir [15:59:10] $

Also, the handling of the condition code behaves differently to other
SIMD instructions -- no error message is produced when assembling an
instruction with a condition code suffix despite the arm encoding not
allowing a condition code. (n.b. the actual binary produced is
independent of the suffix).

The instruction should be treated similarly to VSUBL that has the same
caveat of "must be unconditional" describing the {<c>} symbol.  vcvt
half-precision to single precision found in F6.1.58 in the ARM
Architecture Reference Manual issue C.a, vsubl found in F6.1.240 in
the ARM Architecture Reference Manual issue C.a

2018-11-06  Matthew Malcomson  <matthew.malcomson@arm.com>

	* config/tc-arm.c (do_neon_cvt_1): Add check for neon and condition
	codes to half-precision conversion.
	* testsuite/gas/arm/neon-cond-bad-inc.s: Check vcvteq disallowed.
	* testsuite/gas/arm/neon-cond-bad.l: Likewise.
	* testsuite/gas/arm/neon-cond-bad_t2.d: Check vcvteq allowed in IT
	block.
	* testsuite/gas/arm/vfp-bad.l: Ensure vcvt doesn't work without neon.
	* testsuite/gas/arm/vfp-bad.s: Likewise.

7 files changed, 40 insertions, 14 deletions

diff --git a/gas/ChangeLog b/gas/ChangeLog
index 601f2aa..3aa87c7 100644
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,3 +1,14 @@
+2018-11-06  Matthew Malcomson  <matthew.malcomson@arm.com>
+
+	* config/tc-arm.c (do_neon_cvt_1): Add check for neon and condition
+	codes to half-precision conversion.
+	* testsuite/gas/arm/neon-cond-bad-inc.s: Check vcvteq disallowed.
+	* testsuite/gas/arm/neon-cond-bad.l: Likewise.
+	* testsuite/gas/arm/neon-cond-bad_t2.d: Check vcvteq allowed in IT
+	block.
+	* testsuite/gas/arm/vfp-bad.l: Ensure vcvt doesn't work without neon.
+	* testsuite/gas/arm/vfp-bad.s: Likewise.
+
 2018-11-06  Alan Modra  <amodra@gmail.com>
 
 	* config/tc-ppc.c (insn_validate): Don't ignore mask in
diff --git a/gas/config/tc-arm.c b/gas/config/tc-arm.c
index 80fb0c3..7235b7f 100644
--- a/gas/config/tc-arm.c
+++ b/gas/config/tc-arm.c
@@ -15914,6 +15914,8 @@ do_neon_cvt_1 (enum neon_cvt_mode mode)
     /* Half-precision conversions for Advanced SIMD -- neon.  */
     case NS_QD:
     case NS_DQ:
+      if (vfp_or_neon_is_neon (NEON_CHECK_CC | NEON_CHECK_ARCH) == FAIL)
+	return;
 
       if ((rs == NS_DQ)
 	  && (inst.vectype.el[0].size != 16 || inst.vectype.el[1].size != 32))
diff --git a/gas/testsuite/gas/arm/neon-cond-bad-inc.s b/gas/testsuite/gas/arm/neon-cond-bad-inc.s
index 2f56773..087c529 100644
--- a/gas/testsuite/gas/arm/neon-cond-bad-inc.s
+++ b/gas/testsuite/gas/arm/neon-cond-bad-inc.s
@@ -30,6 +30,10 @@ func:
         dyadic_eq vadd
         dyadic_eq vsub
         
+	itblock 2 eq
+	vcvteq.f16.f32 d1, q1
+	vcvteq.f32.f16 q1, d1
+
 	.macro monadic_eq op eq="eq" f32=".f32"
 	itblock 2 eq
         \op\eq\f32 d0,d1
diff --git a/gas/testsuite/gas/arm/neon-cond-bad.l b/gas/testsuite/gas/arm/neon-cond-bad.l
index a79f79d..331ac7d 100644
--- a/gas/testsuite/gas/arm/neon-cond-bad.l
+++ b/gas/testsuite/gas/arm/neon-cond-bad.l
@@ -13,17 +13,19 @@
 [^:]*:30: Error: instruction cannot be conditional -- `vaddeq\.f32 q0,q1,q2'
 [^:]*:31: Error: instruction cannot be conditional -- `vsubeq\.f32 d0,d1,d2'
 [^:]*:31: Error: instruction cannot be conditional -- `vsubeq\.f32 q0,q1,q2'
-[^:]*:39: Error: instruction cannot be conditional -- `vabseq\.f32 d0,d1'
-[^:]*:39: Error: instruction cannot be conditional -- `vabseq\.f32 q0,q1'
-[^:]*:40: Error: instruction cannot be conditional -- `vnegeq\.f32 d0,d1'
-[^:]*:40: Error: instruction cannot be conditional -- `vnegeq\.f32 q0,q1'
-[^:]*:48: Error: instruction cannot be conditional -- `vcvteq\.s32\.f32 d0,d1'
-[^:]*:48: Error: instruction cannot be conditional -- `vcvteq\.s32\.f32 q0,q1'
-[^:]*:49: Error: instruction cannot be conditional -- `vcvteq\.u32\.f32 d0,d1'
-[^:]*:49: Error: instruction cannot be conditional -- `vcvteq\.u32\.f32 q0,q1'
-[^:]*:50: Error: instruction cannot be conditional -- `vcvteq\.f32\.s32 d0,d1'
-[^:]*:50: Error: instruction cannot be conditional -- `vcvteq\.f32\.s32 q0,q1'
-[^:]*:51: Error: instruction cannot be conditional -- `vcvteq\.f32\.u32 d0,d1'
-[^:]*:51: Error: instruction cannot be conditional -- `vcvteq\.f32\.u32 q0,q1'
-[^:]*:56: Error: instruction cannot be conditional -- `vdupeq\.32 d0,d1\[0\]'
-[^:]*:57: Error: instruction cannot be conditional -- `vdupeq\.32 q0,d1\[1\]'
+[^:]*:34: Error: instruction cannot be conditional -- `vcvteq\.f16\.f32 d1,q1'
+[^:]*:35: Error: instruction cannot be conditional -- `vcvteq\.f32\.f16 q1,d1'
+[^:]*:43: Error: instruction cannot be conditional -- `vabseq\.f32 d0,d1'
+[^:]*:43: Error: instruction cannot be conditional -- `vabseq\.f32 q0,q1'
+[^:]*:44: Error: instruction cannot be conditional -- `vnegeq\.f32 d0,d1'
+[^:]*:44: Error: instruction cannot be conditional -- `vnegeq\.f32 q0,q1'
+[^:]*:52: Error: instruction cannot be conditional -- `vcvteq\.s32\.f32 d0,d1'
+[^:]*:52: Error: instruction cannot be conditional -- `vcvteq\.s32\.f32 q0,q1'
+[^:]*:53: Error: instruction cannot be conditional -- `vcvteq\.u32\.f32 d0,d1'
+[^:]*:53: Error: instruction cannot be conditional -- `vcvteq\.u32\.f32 q0,q1'
+[^:]*:54: Error: instruction cannot be conditional -- `vcvteq\.f32\.s32 d0,d1'
+[^:]*:54: Error: instruction cannot be conditional -- `vcvteq\.f32\.s32 q0,q1'
+[^:]*:55: Error: instruction cannot be conditional -- `vcvteq\.f32\.u32 d0,d1'
+[^:]*:55: Error: instruction cannot be conditional -- `vcvteq\.f32\.u32 q0,q1'
+[^:]*:60: Error: instruction cannot be conditional -- `vdupeq\.32 d0,d1\[0\]'
+[^:]*:61: Error: instruction cannot be conditional -- `vdupeq\.32 q0,d1\[1\]'
diff --git a/gas/testsuite/gas/arm/neon-cond-bad_t2.d b/gas/testsuite/gas/arm/neon-cond-bad_t2.d
index 517caa7..abff084 100644
--- a/gas/testsuite/gas/arm/neon-cond-bad_t2.d
+++ b/gas/testsuite/gas/arm/neon-cond-bad_t2.d
@@ -31,6 +31,9 @@ Disassembly of section \.text:
 0[0-9a-f]+ <[^>]+> ef21 0d02 	vsubeq\.f32	d0, d1, d2
 0[0-9a-f]+ <[^>]+> ef22 0d44 	vsubeq\.f32	q0, q1, q2
 0[0-9a-f]+ <[^>]+> bf04      	itt	eq
+0[0-9a-f]+ <[^>]+> ffb6 1602 	vcvteq.f16.f32	d1, q1
+0[0-9a-f]+ <[^>]+> ffb6 2701 	vcvteq.f32.f16	q1, d1
+0[0-9a-f]+ <[^>]+> bf04      	itt	eq
 0[0-9a-f]+ <[^>]+> ffb9 0701 	vabseq\.f32	d0, d1
 0[0-9a-f]+ <[^>]+> ffb9 0742 	vabseq\.f32	q0, q1
 0[0-9a-f]+ <[^>]+> bf04      	itt	eq
diff --git a/gas/testsuite/gas/arm/vfp-bad.l b/gas/testsuite/gas/arm/vfp-bad.l
index a1479f4..fda2ce4 100644
--- a/gas/testsuite/gas/arm/vfp-bad.l
+++ b/gas/testsuite/gas/arm/vfp-bad.l
@@ -9,3 +9,5 @@
 [^:]*:11: Error: instruction does not support writeback -- `flds s0,\[r0,#-8\]!'
 [^:]*:12: Error: selected FPU does not support instruction -- `vmrs r0,MVFR2'
 [^:]*:13: Error: selected FPU does not support instruction -- `vmsr MVFR2,r2'
+[^:]*:14: Error: selected FPU does not support instruction -- `vcvt.f16.f32 d1,q1'
+[^:]*:15: Error: selected FPU does not support instruction -- `vcvt.f32.f16 q1,d1'
diff --git a/gas/testsuite/gas/arm/vfp-bad.s b/gas/testsuite/gas/arm/vfp-bad.s
index 1a446fe..2a83a21 100644
--- a/gas/testsuite/gas/arm/vfp-bad.s
+++ b/gas/testsuite/gas/arm/vfp-bad.s
@@ -11,3 +11,5 @@ entry:
 	flds	s0, [r0, #-8]!
 	vmrs	r0, MVFR2
 	vmsr	MVFR2, r2
+	vcvt.f16.f32	d1, q1
+	vcvt.f32.f16	q1, d1