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* Allow X86::COND_NE_OR_P and X86::COND_NP_OR_E to be reversed.Cong Hou2016-03-231-3/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, AnalyzeBranch() fails non-equality comparison between floating points on X86 (see https://llvm.org/bugs/show_bug.cgi?id=23875). This is because this function can modify the branch by reversing the conditional jump and removing unconditional jump if there is a proper fall-through. However, in the case of non-equality comparison between floating points, this can turn the branch "unanalyzable". Consider the following case: jne.BB1 jp.BB1 jmp.BB2 .BB1: ... .BB2: ... AnalyzeBranch() will reverse "jp .BB1" to "jnp .BB2" and then "jmp .BB2" will be removed: jne.BB1 jnp.BB2 .BB1: ... .BB2: ... However, AnalyzeBranch() cannot analyze this branch anymore as there are two conditional jumps with different targets. This may disable some optimizations like block-placement: in this case the fall-through behavior is enforced even if the fall-through block is very cold, which is suboptimal. Actually this optimization is also done in block-placement pass, which means we can remove this optimization from AnalyzeBranch(). However, currently X86::COND_NE_OR_P and X86::COND_NP_OR_E are not reversible: there is no defined negation conditions for them. In order to reverse them, this patch defines two new CondCode X86::COND_E_AND_NP and X86::COND_P_AND_NE. It also defines how to synthesize instructions for them. Here only the second conditional jump is reversed. This is valid as we only need them to do this "unconditional jump removal" optimization. Differential Revision: http://reviews.llvm.org/D11393 llvm-svn: 264199
* Revert "Allow X86::COND_NE_OR_P and X86::COND_NP_OR_E to be reversed."Benjamin Kramer2016-01-271-2/+3
| | | | | | | | | and "Add a missing test case for r258847." This reverts commit r258847, r258848. Causes miscompilations and backend errors. llvm-svn: 258927
* Allow X86::COND_NE_OR_P and X86::COND_NP_OR_E to be reversed.Cong Hou2016-01-261-3/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, AnalyzeBranch() fails non-equality comparison between floating points on X86 (see https://llvm.org/bugs/show_bug.cgi?id=23875). This is because this function can modify the branch by reversing the conditional jump and removing unconditional jump if there is a proper fall-through. However, in the case of non-equality comparison between floating points, this can turn the branch "unanalyzable". Consider the following case: jne.BB1 jp.BB1 jmp.BB2 .BB1: ... .BB2: ... AnalyzeBranch() will reverse "jp .BB1" to "jnp .BB2" and then "jmp .BB2" will be removed: jne.BB1 jnp.BB2 .BB1: ... .BB2: ... However, AnalyzeBranch() cannot analyze this branch anymore as there are two conditional jumps with different targets. This may disable some optimizations like block-placement: in this case the fall-through behavior is enforced even if the fall-through block is very cold, which is suboptimal. Actually this optimization is also done in block-placement pass, which means we can remove this optimization from AnalyzeBranch(). However, currently X86::COND_NE_OR_P and X86::COND_NP_OR_E are not reversible: there is no defined negation conditions for them. In order to reverse them, this patch defines two new CondCode X86::COND_E_AND_NP and X86::COND_P_AND_NE. It also defines how to synthesize instructions for them. Here only the second conditional jump is reversed. This is valid as we only need them to do this "unconditional jump removal" optimization. Differential Revision: http://reviews.llvm.org/D11393 llvm-svn: 258847
* Change the fast-isel-abort option from bool to int to enable "levels"Mehdi Amini2015-02-271-1/+1
| | | | | | | | | | | | | | | | | | | | | | | Summary: Currently fast-isel-abort will only abort for regular instructions, and just warn for function calls, terminators, function arguments. There is already fast-isel-abort-args but nothing for calls and terminators. This change turns the fast-isel-abort options into an integer option, so that multiple levels of strictness can be defined. This will help no being surprised when the "abort" option indeed does not abort, and enables the possibility to write test that verifies that no intrinsics are forgotten by fast-isel. Reviewers: resistor, echristo Subscribers: jfb, llvm-commits Differential Revision: http://reviews.llvm.org/D7941 From: Mehdi Amini <mehdi.amini@apple.com> llvm-svn: 230775
* Reapply [FastISel][X86] Use XOR to materialize the "0" value (r215594).Juergen Ributzka2014-08-191-5/+5
| | | | | | | Note: This was originally reverted to track down a buildbot error. Reapply without any modifications. llvm-svn: 216011
* Revert several FastISel commits to track down a buildbot error.Juergen Ributzka2014-08-141-5/+5
| | | | | | | | | | | | This reverts: r215595 "[FastISel][X86] Add large code model support for materializing floating-point constants." r215594 "[FastISel][X86] Use XOR to materialize the "0" value." r215593 "[FastISel][X86] Emit more efficient instructions for integer constant materialization." r215591 "[FastISel][AArch64] Make use of the zero register when possible." r215588 "[FastISel] Let the target decide first if it wants to materialize a constant." r215582 "[FastISel][AArch64] Cleanup constant materialization code. NFCI." llvm-svn: 215673
* [FastISel][X86] Use XOR to materialize the "0" value.Juergen Ributzka2014-08-131-5/+5
| | | | llvm-svn: 215594
* [FastISel][X86] Optimize predicates and fold CMP instructions.Juergen Ributzka2014-06-171-0/+470
This optimizes predicates for certain compares, such as fcmp oeq %x, %x to fcmp ord %x, %x. The latter one is more efficient to generate. The same optimization is applied to conditional branches. llvm-svn: 211126
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