xref: /llvm-project/llvm/test/CodeGen/WebAssembly/PR40172.ll (revision c65b4d64d4b09795fe237b62a4226121c5b13248)
1; RUN: llc < %s -O0 -wasm-disable-explicit-locals -wasm-keep-registers | FileCheck %s
2
3; Regression test for bug 40172. The problem was that FastISel assumed
4; that CmpInst results did not need to be zero extended because
5; WebAssembly's compare instructions always return 0 or 1. But in this
6; test case FastISel falls back to DAG ISel, which combines away the
7; comparison, invalidating FastISel's assumption.
8
9target triple = "wasm32-unknown-unknown"
10
11; CHECK:  i32.sub $[[BASE:[0-9]+]]=,
12; CHECK:  local.copy $[[ARG:[0-9]+]]=, $0{{$}}
13; CHECK:  i32.const $[[A0:[0-9]+]]=, 1{{$}}
14; CHECK:  i32.and $[[A1:[0-9]+]]=, $[[ARG]], $[[A0]]{{$}}
15; CHECK:  i32.store8 8($[[BASE]]), $[[A1]]{{$}}
16
17define void @test(i8 %byte) {
18  %t = alloca { i8, i8 }, align 8
19  %x4 = and i8 %byte, 1
20  %x5 = icmp eq i8 %x4, 1
21  %x6 = and i8 %byte, 2
22  %x7 = icmp eq i8 %x6, 2
23  %x9 = zext i1 %x5 to i8
24  store i8 %x9, ptr %t, align 1
25  %x10 = getelementptr inbounds { i8, i8 }, ptr %t, i32 0, i32 1
26  %x11 = zext i1 %x7 to i8
27  store i8 %x11, ptr %x10, align 1
28  ret void
29}
30