Changes

Summary

[WC] Fix a subtle bug in our definition of widenable branch (details)
[JumpThreading] Factor out code to clone instructions (NFC) (details)
[Orc] Fix iterator usage after remove (details)

Commit 686f449e3d4ecad6413427aef35557f5adac100c by listmail [WC] Fix a subtle bug in our definition of widenable branch We had a subtle, but nasty bug in our definition of a widenable branch, and thus in the transforms which used that utility. Specifically, we returned true for any branch which included a widenable condition within it's condition, regardless of whether that widenable condition also had other uses. The problem is that the result of the WC() call is defined to be one particular value. As such, all users must agree as to what that value is. If we widen a branch without also updating all other users of the WC in the same way, we have broken the required semantics. Most of the textual diff is updating existing transforms not to leave dead uses hanging around. They're largely NFC as the dead instructions would be immediately deleted by other passes. The reason to make these changes is so that the transforms preserve the widenable branch form. In practice, we don't get bitten by this only because it isn't profitable to CSE WC() calls and the lowering pass from guards uses distinct WC calls per branch. Differential Revision: https://reviews.llvm.org/D69916
	llvm/lib/Analysis/GuardUtils.cpp
	llvm/lib/Transforms/Scalar/GuardWidening.cpp
	llvm/lib/Transforms/Scalar/LoopPredication.cpp
	llvm/test/Transforms/GuardWidening/basic_widenable_condition_guards.ll
	llvm/test/Transforms/GuardWidening/mixed_guards.ll
	llvm/test/Transforms/SimplifyCFG/wc-widen-block.ll
Commit f0f73ed8b004d213a3710b7b850e09c5bbd8e93d by kazu [JumpThreading] Factor out code to clone instructions (NFC) Summary: This patch factors out code to clone instructions -- partly for readability and partly to facilitate an upcoming patch of my own. Reviewers: wmi Subscribers: hiraditya, jfb, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D69861
	llvm/lib/Transforms/Scalar/JumpThreading.cpp
	llvm/include/llvm/Transforms/Scalar/JumpThreading.h
Commit 007d173e2e0c29903bc17a9d5108f531a6f2ea4d by alexandre.ganea [Orc] Fix iterator usage after remove Differential Revision: https://reviews.llvm.org/D69805
	llvm/lib/ExecutionEngine/Orc/Core.cpp