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An unimp instruction occurs while compiling the v instruction with clang, causing QEMU to report an error: an illegal instruction error #80112

Open 24geng opened 7 months ago

24geng commented 7 months ago

Can someone please tell me why that is? I would appreciate it!

My compile options: clang++ -g --target=riscv64-unknown-linux-gnu -march=rv64imafdcv -mrvv-vector-bits=128 20230329.cpp -o 20230329 -stdlib=libc++

00000000000016f8 <_start>: 16f8: ef 00 20 02 jal 0x171a 16fc: aa 87 mv a5, a0 16fe: 17 f5 00 00 auipc a0, 15 1702: 03 35 25 a2 ld a0, -1502(a0) 1706: 82 65 ld a1, 0(sp) 1708: 30 00 addi a2, sp, 8 170a: 13 71 01 ff andi sp, sp, -16 170e: 81 46 li a3, 0 1710: 01 47 li a4, 0 1712: 0a 88 mv a6, sp 1714: ef f0 df d9 jal 0x14b0 <.plt+0xe0> 1718: 02 90 ebreak

000000000000171a : 171a: 97 f1 00 00 auipc gp, 15 171e: 93 81 61 0e addi gp, gp, 230 1722: 82 80 ret 1724: 00 00 unimp

c444: 13 01 01 fc addi sp, sp, -64 c448: 23 3c 11 02 sd ra, 56(sp) c44c: 23 38 81 02 sd s0, 48(sp) c450: 13 04 01 04 addi s0, sp, 64 c454: 13 01 01 fe addi sp, sp, -32 c458: 23 34 a4 fc sd a0, -56(s0) c45c: 23 30 b4 fc sd a1, -64(s0) c460: 03 35 84 fc ld a0, -56(s0) c464: 83 35 04 fc ld a1, -64(s0) c468: 57 70 02 cd vsetivli zero, 4, e32, m1, ta, ma c46c: 07 e4 05 02 vle32.v v8, (a1) c470: 23 30 a4 fe sd a0, -32(s0) c474: 93 05 04 fa addi a1, s0, -96 c478: 27 84 85 02 vs1r.v v8, (a1) c47c: 13 05 40 00 li a0, 4 c480: 23 2e a4 fc sw a0, -36(s0) c484: 03 25 c4 fd lw a0, -36(s0) c488: 57 75 05 0d vsetvli a0, a0, e32, m1, ta, ma c48c: 23 38 a4 fc sd a0, -48(s0) c490: 03 35 04 fe ld a0, -32(s0) c494: 07 e4 85 02 vl1re32.v v8, (a1) c498: 83 35 04 fd ld a1, -48(s0) c49c: 57 f0 05 0d vsetvli zero, a1, e32, m1, ta, ma c4a0: 27 64 05 02 vse32.v v8, (a0) c4a4: 73 10 00 c0 unimp

topperc commented 7 months ago

Best guess, the compiler has decided that the code has undefined behavior or something and has decided to generate a trap there.

Can you share your code?