; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 4
; RUN: llc < %s -mtriple=riscv64 -mattr=+v -riscv-v-vector-bits-max=128 -verify-machineinstrs | FileCheck %s
; This showcases a miscompile that was fixed in #83107:
; - The memset will be type-legalized to a 512 bit store + 2 x 128 bit stores.
; - the load and store of q aliases the upper 128 bits store of p.
; - The aliasing 128 bit store will be between the chain of the scalar
; load/store:
;
; t54: ch = store<(store (s512) into %ir.p, align 1)> t0, ...
; t51: ch = store<(store (s128) into %ir.p + 64, align 1)> t0, ...
;
; t44: i64,ch = load<(load (s32) from %ir.q), sext from i32> t0, ...
; t50: ch = store<(store (s128) into %ir.p + 80, align 1)> t44:1, ...
; t46: ch = store<(store (s32) into %ir.q), trunc to i32> t50, ...
;
; Previously, the scalar load/store was incorrectly combined away:
;
; t54: ch = store<(store (s512) into %ir.p, align 1)> t0, ...
; t51: ch = store<(store (s128) into %ir.p + 64, align 1)> t0, ...
;
; // MISSING
; t50: ch = store<(store (s128) into %ir.p + 80, align 1)> t44:1, ...
; // MISSING
;
; - We need to compile with an exact VLEN so that we select an ISD::STORE node
; which triggers the combine
; - The miscompile doesn't happen if we use separate GEPs as we need the stores
; to share the same MachinePointerInfo
define void @aliasing(ptr %p) {
; CHECK-LABEL: aliasing:
; CHECK: # %bb.0:
; CHECK-NEXT: lw a1, 84(a0)
; CHECK-NEXT: addi a2, a0, 80
; CHECK-NEXT: vsetivli zero, 16, e8, m1, ta, ma
; CHECK-NEXT: vmv.v.i v8, 0
; CHECK-NEXT: vs1r.v v8, (a2)
; CHECK-NEXT: addi a2, a0, 64
; CHECK-NEXT: vs1r.v v8, (a2)
; CHECK-NEXT: vsetvli a2, zero, e8, m4, ta, ma
; CHECK-NEXT: vmv.v.i v8, 0
; CHECK-NEXT: vs4r.v v8, (a0)
; CHECK-NEXT: sw a1, 84(a0)
; CHECK-NEXT: ret
%q = getelementptr inbounds i8, ptr %p, i64 84
%tmp = load i32, ptr %q
tail call void @llvm.memset.p0.i64(ptr %p, i8 0, i64 96, i1 false)
store i32 %tmp, ptr %q
ret void
}
Codebase Browser
llvm