vid.v causes hang in vsim/verilator

[fabriziocabaleiro]

Tested with commit e970f77, vid.v causes a hang in both vsim and verilator.

I did not use the build system from the app folder because it gave me some errors I don't remember now.

I copied crt0.S and the linker script from the app folder and set the linker script to align for 4 lanes (default).

I tried to keep the test as simple as possible while testing few other vector instructions.

main.S is as follow (also included in tar.gz)

.global main
.type main, @function

.section .text
main:
	vsetvli		t0, zero, e16, m4, ta, ma
	vmv.v.i		v0, 2
	vwmul.vx	v8, v0, zero
#ifdef HANG
	vid.v		v0
#endif
	vadd.vi		v0, v0, 1
	vadd.vi		v0, v0, -1
	vadd.vx		v0, v0, t0
	vsub.vx		v0, v0, t0
	vslidedown.vi	v16, v0, 2 // elem[0] = 2
	addi		t0, zero, 2
.rept 10
	vwmacc.vx	v8, t0, v16 // elem[0] = 10*2*2
.endr
	vsetvli		t0, zero, e32, m8, ta, ma
	vmv.x.s		a0, v8
	// return value = elem[0] - 40; should be a0 = 0
	addi		a0, a0, -40
	ret
.size main,.-main

.end

The attached makefile generates both no_hang.elf and hang.elf. no_hang.elf should finish successfully and hang.elf should hang.
hang.elf works fine when compiled for and run in spike.

Test source files ara_vid_hang.tar.gz