ARM: correct handling of features in arch_extension

The subtarget information is the ultimate source of truth for the feature set
that is enabled at this point.  We would previously not propagate the feature
information to the subtarget.  While this worked for the most part (features
would be enabled/disabled as requested), if another operation that changed the
feature bits was encountered (such as a mode switch via a .arm or .thumb
directive), we would end up resetting the behaviour of the architectural
extensions.

Handling this properly requires a slightly more complicated handling.  We need
to check if the feature is now being toggled.  If so, only then do we toggle the
features.  In return, we no longer have to calculate the feature bits ourselves.

The test changes are mostly to the diagnosis, which is now more uniform (a nice
side effect!).  Add an additional test to ensure that we handle this case
properly.

Thanks to Nico Weber for alerting me to this issue!

llvm-svn: 214057

1 files changed, 65 insertions, 126 deletions

diff --git a/llvm/test/MC/ARM/directive-arch_extension-fp.s b/llvm/test/MC/ARM/directive-arch_extension-fp.s
index 0327dd74337..f2b4dc2c412 100644
--- a/llvm/test/MC/ARM/directive-arch_extension-fp.s
+++ b/llvm/test/MC/ARM/directive-arch_extension-fp.s
@@ -1,11 +1,11 @@
 @ RUN: not llvm-mc -triple armv7-eabi -filetype asm -o /dev/null 2>&1 %s \
-@ RUN:   | FileCheck %s -check-prefix CHECK-V7
+@ RUN:   | FileCheck %s -check-prefix CHECK-V7 -check-prefix CHECK
 @ RUN: not llvm-mc -triple armv8-eabi -filetype asm -o /dev/null 2>&1 %s \
-@ RUN:   | FileCheck %s -check-prefix CHECK-V8
+@ RUN:   | FileCheck %s -check-prefix CHECK-V8 -check-prefix CHECK
 @ RUN: not llvm-mc -triple thumbv7-eabi -filetype asm -o /dev/null 2>&1 %s \
-@ RUN:   | FileCheck %s -check-prefix CHECK-V7
+@ RUN:   | FileCheck %s -check-prefix CHECK-V7 -check-prefix CHECK
 @ RUN: not llvm-mc -triple thumbv8-eabi -filetype asm -o /dev/null 2>&1 %s \
-@ RUN:   | FileCheck %s -check-prefix CHECK-V8
+@ RUN:   | FileCheck %s -check-prefix CHECK-V8 -check-prefix CHECK
 
 	.syntax unified
 
@@ -153,192 +153,131 @@ fp:
 	.type nofp,%function
 nofp:
 	vmrs r0, mvfr2
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 
 	vselgt.f32 s0, s0, s0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vselge.f32 s0, s0, s0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vseleq.f32 s0, s0, s0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vselvs.f32 s0, s0, s0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vmaxnm.f32 s0, s0, s0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vminnm.f32 s0, s0, s0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 
 	vselgt.f64 d0, d0, d0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: double precision VFP FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vselge.f64 d0, d0, d0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: double precision VFP FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vseleq.f64 d0, d0, d0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: double precision VFP FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vselvs.f64 d0, d0, d0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: double precision VFP FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vmaxnm.f64 d0, d0, d0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: double precision VFP FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vminnm.f64 d0, d0, d0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: double precision VFP FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 
 	vcvtb.f64.f16 d0, s0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: double precision VFP FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vcvtb.f16.f64 s0, d0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: double precision VFP FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vcvtt.f64.f16 d0, s0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: double precision VFP FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vcvtt.f16.f64 s0, d0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: double precision VFP FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 
 	vcvta.s32.f32 s0, s0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vcvta.u32.f32 s0, s0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vcvta.s32.f64 s0, d0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: double precision VFP FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vcvta.u32.f64 s0, d0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: double precision VFP FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vcvtn.s32.f32 s0, s0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vcvtn.u32.f32 s0, s0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vcvtn.s32.f64 s0, d0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: double precision VFP FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vcvtn.u32.f64 s0, d0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: double precision VFP FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vcvtp.s32.f32 s0, s0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vcvtp.u32.f32 s0, s0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vcvtp.s32.f64 s0, d0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: double precision VFP FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vcvtp.u32.f64 s0, d0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: double precision VFP FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vcvtm.s32.f32 s0, s0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vcvtm.u32.f32 s0, s0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vcvtm.s32.f64 s0, d0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: double precision VFP FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vcvtm.u32.f64 s0, d0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: double precision VFP FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 
 	vrintz.f32 s0, s1
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vrintz.f64 d0, d1
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: double precision VFP FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vrintz.f32.f32 s0, s0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vrintz.f64.f64 d0, d0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: double precision VFP FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vrintr.f32 s0, s1
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vrintr.f64 d0, d1
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: double precision VFP FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vrintr.f32.f32 s0, s0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vrintr.f64.f64 d0, d0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: double precision VFP FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vrintx.f32 s0, s1
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vrintx.f64 d0, d1
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: double precision VFP FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vrintx.f32.f32 s0, s0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vrintx.f64.f64 d0, d0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: double precision VFP FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 
 	vrinta.f32 s0, s0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vrinta.f64 d0, d0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: double precision VFP FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vrinta.f32.f32 s0, s0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vrinta.f64.f64 d0, d0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: double precision VFP FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vrintn.f32 s0, s0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vrintn.f64 d0, d0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: double precision VFP FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vrintn.f32.f32 s0, s0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vrintn.f64.f64 d0, d0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: double precision VFP FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vrintp.f32 s0, s0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vrintp.f64 d0, d0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: double precision VFP FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vrintp.f32.f32 s0, s0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vrintp.f64.f64 d0, d0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: double precision VFP FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vrintm.f32 s0, s0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vrintm.f64 d0, d0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: double precision VFP FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vrintm.f32.f32 s0, s0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: FPARMv8
+@ CHECK: error: instruction requires: FPARMv8
 	vrintm.f64.f64 d0, d0
-@ CHECK-V7: error: instruction requires: FPARMv8
-@ CHECK-V8: error: instruction requires: double precision VFP FPARMv8
+@ CHECK: error: instruction requires: FPARMv8