[PATCH] D139530: [WebAssembly] Add ComplexPattern for loads

[Luke Lau via Phabricator via llvm-commits]

luke marked an inline comment as not done.
luke added inline comments.


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Comment at: llvm/lib/Target/WebAssembly/WebAssemblyISelDAGToDAG.cpp:360-361
+
+  // Likewise, treat an 'or' node as an 'add' if the or'ed bits are
+  // known to be zero and fold them into the offset too.
+  if (N.getOpcode() == ISD::OR) {
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tlively wrote:
> Do we have tests covering these cases?
I believe so in `test/CodeGen/WebAssembly/offset.ll` with the functions ending in `with_folded_or_offset`


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Comment at: llvm/lib/Target/WebAssembly/WebAssemblyRegisterInfo.cpp:79
+    auto &OffsetOp = MI.getOperand(OffsetOperandNum);
+    // Don't fold offset in if offset is a global address to be resolved later
+    if (OffsetOp.isImm()) {
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tlively wrote:
> What's the benefit of this extra logic?
Now that (add tga x) is now selected into something like `i32.load offset=tga, x`, the above assertion was being triggered because it assumed that any `offset` operand would always be an immediate, not a target global address. So this just wraps around it.
I'm not 100% sure as to why this is only triggered now with this patch as I'm fairly certain there were loads being selected like `i32.load offset=tga, 0`


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D139530/new/

https://reviews.llvm.org/D139530