[PATCH] D84405: CodeGen: Improve generated IR for __builtin_mul_overflow(uint, uint, int)

Thu Jul 23 10:26:28 PDT 2020

vsk added a comment.

How were you able to show that the specialized IRGen is equivalent to the generic kind? I tried doing this with direct inspection (https://godbolt.org/z/o5WEn3), but wasn't able to convince myself. In the past I used a test driver to compare the before/after compiler output -- you might find that useful (https://gist.github.com/vedantk/3eb9c88f82e5c32f2e590555b4af5081).

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Comment at: clang/test/CodeGen/builtins-overflow.c:123
+  // CHECK: br i1 [[C2]]
+  int r;
+  if (__builtin_mul_overflow(x, y, &r))
----------------
Could you add a test for the volatile result case?

Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D84405/new/

https://reviews.llvm.org/D84405