Clang crashes compiling valgrind Thumb2/arm

[kraj]

Bugzilla Link	40036
Version	7.0
OS	All
Attachments	shell script, testcase
CC	@rovka,@efriedma-quic,@rengolin,@zygoloid,@smithp35

Extended Description

Attached testcase and script to run the compiler

[efriedma-quic]

I see a three issues here:

1. ARMTargetLowering::getRegForInlineAsmConstraint should handle "w" with an integer input (by returning &ARM::SPRRegClass and letting SelectionDAGBuilder insert the appropriate cast).
2. patchMatchingInput in SelectionDAGBuilder.cpp emits a spurious error message if you try to match an i32 with a f32, even if they would otherwise be compatible.
3. patchMatchingInput should use emitInlineAsmError to emit error messages on invalid inline asm, not report_fatal_error.

[rengolin]

I think the error is about int input with float output.

My inline-asm-fu is very rusty, but that sounds to me like a valid use of vcvt.

[rengolin]

This is the reduced case: a() { int b; float c; asm("" : "=w"(c) : "0"(b)); }

$ clang -target thumbv7ve-yoe-linux-musleabi -c vcvt_fixed_float_VFP-b24785.c vcvt_fixed_float_VFP-b24785.c:1:1: warning: type specifier missing, defaults to 'int' [-Wimplicit-int] a() { ^ vcvt_fixed_float_VFP-b24785.c:5:1: warning: control reaches end of non-void function [-Wreturn-type] } ^ fatal error: error in backend: Unsupported asm: input constraint with a matching output constraint of incompatible type!

[rengolin]

I'm getting:

fatal error: error in backend: Unsupported asm: input constraint with a matching output constraint of incompatible type!

Is that what you see, too?