1; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 5 2; RUN: llc < %s -mtriple=riscv64 -mattr=+v -verify-machineinstrs | FileCheck %s 3 4; Use cttz to test if we properly prove never-zero. There is a very 5; simple transform from cttz -> cttz_zero_undef if its operand is 6; known never zero. 7 8; Even without vscale_range, vscale is always guaranteed to be non-zero. 9define i32 @vscale_known_nonzero() { 10; CHECK-LABEL: vscale_known_nonzero: 11; CHECK: # %bb.0: 12; CHECK-NEXT: addi sp, sp, -16 13; CHECK-NEXT: .cfi_def_cfa_offset 16 14; CHECK-NEXT: sd ra, 8(sp) # 8-byte Folded Spill 15; CHECK-NEXT: .cfi_offset ra, -8 16; CHECK-NEXT: csrr a0, vlenb 17; CHECK-NEXT: srli a0, a0, 3 18; CHECK-NEXT: neg a1, a0 19; CHECK-NEXT: and a0, a0, a1 20; CHECK-NEXT: lui a1, 30667 21; CHECK-NEXT: addiw a1, a1, 1329 22; CHECK-NEXT: call __muldi3 23; CHECK-NEXT: srliw a0, a0, 27 24; CHECK-NEXT: lui a1, %hi(.LCPI0_0) 25; CHECK-NEXT: addi a1, a1, %lo(.LCPI0_0) 26; CHECK-NEXT: add a0, a1, a0 27; CHECK-NEXT: lbu a0, 0(a0) 28; CHECK-NEXT: ld ra, 8(sp) # 8-byte Folded Reload 29; CHECK-NEXT: .cfi_restore ra 30; CHECK-NEXT: addi sp, sp, 16 31; CHECK-NEXT: .cfi_def_cfa_offset 0 32; CHECK-NEXT: ret 33 %x = call i32 @llvm.vscale() 34 %r = call i32 @llvm.cttz.i32(i32 %x, i1 false) 35 ret i32 %r 36} 37