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https://github.com/RPCS3/llvm.git
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Roman Lebedev
ee2422df6a
Summary:
Now that with D65143/D65144 we've produce `@llvm.umul.with.overflow`,
and with D65147 we've flattened the CFG, we now can see that
the guard may have been there to prevent division by zero is redundant.
We can simply drop it:
```
----------------------------------------
Name: no overflow and not zero
%iszero = icmp ne i4 %y, 0
%umul = umul_overflow i4 %x, %y
%umul.ov = extractvalue {i4, i1} %umul, 1
%retval.0 = and i1 %iszero, %umul.ov
ret i1 %retval.0
=>
%iszero = icmp ne i4 %y, 0
%umul = umul_overflow i4 %x, %y
%umul.ov = extractvalue {i4, i1} %umul, 1
%retval.0 = and i1 %iszero, %umul.ov
ret %umul.ov
Done: 1
Optimization is correct!
```
Reviewers: nikic, spatel, xbolva00
Reviewed By: spatel
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D65150
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@370350 91177308-0d34-0410-b5e6-96231b3b80d8