llvm-6502/test/MC/ARM/directive-arch_extension-mode-switch.s

@ RUN: not llvm-mc -triple armv8-eabi -filetype asm -o /dev/null %s 2>&1 | FileCheck %s

@ Ensure that a mode switch does not revert the architectural features that were
@ alternated explicitly.

	.syntax unified

	.arch_extension noidiv

	.arm
	udiv r0, r0, r1
@ CHECK: instruction requires: divide in ARM

	.thumb
	udiv r0, r0, r1
@ CHECK: instruction requires: divide in THUMB
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! git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214057 91177308-0d34-0410-b5e6-96231b3b80d8 2014-07-27 19:07:09 +00:00			`@ RUN: not llvm-mc -triple armv8-eabi -filetype asm -o /dev/null %s 2>&1 \| FileCheck %s`

			`@ Ensure that a mode switch does not revert the architectural features that were`
			`@ alternated explicitly.`

			`.syntax unified`

			`.arch_extension noidiv`

			`.arm`
			`udiv r0, r0, r1`
			`@ CHECK: instruction requires: divide in ARM`

			`.thumb`
			`udiv r0, r0, r1`
			`@ CHECK: instruction requires: divide in THUMB`