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* [SimplifyLibCalls] Mark known arguments with nonnullDavid Bolvansky2019-09-171-3/+43
| | | | | | | | | | | | Reviewers: efriedma, jdoerfert Reviewed By: jdoerfert Subscribers: ychen, rsmith, joerg, aaron.ballman, lebedev.ri, uenoku, jdoerfert, hfinkel, javed.absar, spatel, dmgreen, llvm-commits Differential Revision: https://reviews.llvm.org/D53342 llvm-svn: 372091
* [SimplifyLibCalls] Add dereferenceable bytes from known callsitesDavid Bolvansky2019-08-131-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: int mm(char *a, char *b) { return memcmp(a,b,16); } Currently: define dso_local i32 @mm(i8* nocapture readonly %a, i8* nocapture readonly %b) local_unnamed_addr #1 { entry: %call = tail call i32 @memcmp(i8* %a, i8* %b, i64 16) ret i32 %call } After patch: define dso_local i32 @mm(i8* nocapture readonly %a, i8* nocapture readonly %b) local_unnamed_addr #1 { entry: %call = tail call i32 @memcmp(i8* dereferenceable(16) %a, i8* dereferenceable(16) %b, i64 16) ret i32 %call } Reviewers: jdoerfert, efriedma Reviewed By: jdoerfert Subscribers: javed.absar, spatel, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D66079 llvm-svn: 368657
* Revert "Temporarily Revert "Add basic loop fusion pass.""Eric Christopher2019-04-171-0/+204
| | | | | | | | The reversion apparently deleted the test/Transforms directory. Will be re-reverting again. llvm-svn: 358552
* Temporarily Revert "Add basic loop fusion pass."Eric Christopher2019-04-171-204/+0
| | | | | | | | As it's causing some bot failures (and per request from kbarton). This reverts commit r358543/ab70da07286e618016e78247e4a24fcb84077fda. llvm-svn: 358546
* [SimplifyLibCalls] Fix memchr expansion for constant strings.Eli Friedman2019-01-091-16/+19
| | | | | | | | | | | | The C standard says "The memchr function locates the first occurrence of c (converted to an unsigned char)[...]". The expansion was missing the conversion to unsigned char. Fixes https://bugs.llvm.org/show_bug.cgi?id=39041 . Differential Revision: https://reviews.llvm.org/D55947 llvm-svn: 350775
* SimplifyLibCalls: Optimize wcslenMatthias Braun2017-05-191-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | Refactor the strlen optimization code to work for both strlen and wcslen. This especially helps with programs in the wild where people pass L"string"s to const std::wstring& function parameters and the wstring constructor gets inlined. This also fixes a lingerind API problem/bug in getConstantStringInfo() where zeroinitializers would always give you an empty string (without a length) back regardless of the actual length of the initializer which did not work well in the TrimAtNul==false causing the PR mentioned below. Note that the fixed getConstantStringInfo() needed fixes to SelectionDAG memcpy lowering and may lead to some cases for out-of-bounds zeroinitializer accesses not getting optimized anymore. So some code with UB may produce out of bound memory reads now instead of just producing zeros. The refactoring "accidentally" fixes http://llvm.org/PR32124 Differential Revision: https://reviews.llvm.org/D32839 llvm-svn: 303461
* [InstCombine] regenerate checksSanjay Patel2016-05-021-81/+73
| | | | llvm-svn: 268244
* [SimplifyLibCalls] Fix negative shifts being produced by the memchr -> ↵Benjamin Kramer2015-03-211-0/+12
| | | | | | bitfield transform. llvm-svn: 232903
* [SimplifyLibCalls] Turn memchr(const, C, const) into a bitfield check.Benjamin Kramer2015-03-211-1/+68
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | strchr("123!", C) != nullptr is a common pattern to check if C is one of 1, 2, 3 or !. If the largest element of the string is smaller than the target's register size we can easily create a bitfield and just do a simple test for set membership. int foo(char C) { return strchr("123!", C) != nullptr; } now becomes cmpl $64, %edi ## range check sbbb %al, %al movabsq $0xE000200000001, %rcx btq %rdi, %rcx ## bit test sbbb %cl, %cl andb %al, %cl ## and the two conditions andb $1, %cl movzbl %cl, %eax ## returning an int ret (imho the backend should expand this into a series of branches, but that's a different story) The code is currently limited to bit fields that fit in a register, so usually 64 or 32 bits. Sadly, this misses anything using alpha chars or {}. This could be fixed by just emitting a i128 bit field, but that can generate really ugly code so we have to find a better way. To some degree this is also recreating switch lowering logic, but we can't simply emit a switch instruction and thus change the CFG within instcombine. llvm-svn: 232902
* SimplifyLibCalls: Add basic optimization of memchr calls.Benjamin Kramer2015-03-211-0/+121
This is just memchr(x, y, 0) -> nullptr and constant folding. llvm-svn: 232896
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