emmettneyman added a comment.
In https://reviews.llvm.org/D50670#1200784, @morehouse wrote:
> Does this hit new coverage in the vectorizer?
Yes, this does hit new coverage in the loop vectorizer code.
================
Comment at: clang/tools/clang-fuzzer/proto-to-llvm/loop_proto_to_llvm.cpp:131
std::ostream &operator<<(std::ostream &os, const LoopFunction &x) {
- return os << "target triple = \"x86_64-unknown-linux-gnu\"\n"
- << "define void @foo(i32* %a, i32* %b, i32* %c, i64 %s) {\n"
- << "%1 = icmp sgt i64 %s, 0\n"
- << "br i1 %1, label %start, label %end\n"
- << "start:\n"
- << "br label %loop\n"
- << "end:\n"
- << "ret void\n"
- << "loop:\n"
- << " %ct = phi i64 [ %ctnew, %loop ], [ 0, %start ]\n"
- << x.statements()
- << "%ctnew = add i64 %ct, 1\n"
- << "%j = icmp eq i64 %ctnew, %s\n"
- << "br i1 %j, label %end, label %loop, !llvm.loop !0\n}\n"
- << "!0 = distinct !{!0, !1, !2}\n"
- << "!1 = !{!\"llvm.loop.vectorize.enable\", i1 true}\n"
- << "!2 = !{!\"llvm.loop.vectorize.width\", i32 " << kArraySize
- << "}\n";
+ os << "target triple = \"x86_64-pc-linux-gnu\"\n"
+ << "define void @foo(i32* %a, i32* %b, i32* noalias %c, i64 %s) {\n"
----------------
morehouse wrote:
> Why do you change this to `pc` again?
Sorry, it got changed back when I copy/pasted the IR.
================
Comment at: clang/tools/clang-fuzzer/proto-to-llvm/loop_proto_to_llvm.cpp:136
+ << "outer_loop_start:\n"
+ << "br label %inner_loop_start\n"
+ << "inner_loop_start:\n"
----------------
morehouse wrote:
> Looks like a pointless branch.
I realize it's just a label with a branch instruction but I think I need it for
the phi instruction. I will move the `outer_loop_start` label above the `icmp`
instruction and change the branch from `outer_loop_start` to `inner_loop_start`.
================
Comment at: clang/tools/clang-fuzzer/proto-to-llvm/loop_proto_to_llvm.cpp:144
+ << x.outer_statements()
+ << "%o_ct_new = add nuw nsw i64 %outer_ct, 1\n"
+ << "%jmp_outer = icmp eq i64 %o_ct_new, %s\n"
----------------
morehouse wrote:
> Why `nuw`, `nsw` here?
Sorry, it got changed back when I copy/pasted the IR.
================
Comment at: clang/tools/clang-fuzzer/proto-to-llvm/loop_proto_to_llvm.cpp:154
+ << "}\n"
+ << "!0 = distinct !{!0, !1, !2}\n"
+ << "!1 = !{!\"llvm.loop.vectorize.enable\", i1 true}\n"
----------------
morehouse wrote:
> Can we simplify the order of blocks here? It is confusing to follow all
> these jumps forward and backward.
Yes, I think it might be cleaner to have the blocks like this:
```
define @foo... {
outer_loop_start
outer_loop
inner_loop_start
inner_loop
end
}
```
Repository:
rC Clang
https://reviews.llvm.org/D50670
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