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path: root/lib/Transforms/Utils/BypassSlowDivision.cpp
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2012-10-04This patch corrects commit 165126 by using an integer bit width instead of Preston Gurd
a pointer to a type, in order to remove the uses of getGlobalContext(). Patch by Tyler Nowicki. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165255 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-03This Patch corrects a problem whereby the optimization to use a faster dividePreston Gurd
instruction (for Intel Atom) was not being done by Clang, because the type context used by Clang is not the default context. It fixes the problem by getting the global context types for each div/rem instruction in order to compare them against the types in the BypassTypeMap. Tests for this will be done as a separate patch to Clang. Patch by Tyler Nowicki. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165126 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-14Stylistic and 80-col fixesEvan Cheng
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163940 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-10Move bypassSlowDivision into the llvm namespace.Benjamin Kramer
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163503 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-04BypassSlowDivision: Assign to reference, don't copy the object.Jakub Staszak
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163179 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-04Fix my previous patch (r163164). It does now what it is supposed to do:Jakub Staszak
Doesn't set MadeChange to TRUE if BypassSlowDivision doesn't change anything. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163165 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-04Return false if BypassSlowDivision doesn't change anything.Jakub Staszak
Also a few minor changes: - use pre-inc instead of post-inc - use isa instead of dyn_cast - 80 col - trailing spaces git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163164 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-04Generic Bypass Slow DivPreston Gurd
- CodeGenPrepare pass for identifying div/rem ops - Backend specifies the type mapping using addBypassSlowDivType - Enabled only for Intel Atom with O2 32-bit -> 8-bit - Replace IDIV with instructions which test its value and use DIVB if the value is positive and less than 256. - In the case when the quotient and remainder of a divide are used a DIV and a REM instruction will be present in the IR. In the non-Atom case they are both lowered to IDIVs and CSE removes the redundant IDIV instruction, using the quotient and remainder from the first IDIV. However, due to this optimization CSE is not able to eliminate redundant IDIV instructions because they are located in different basic blocks. This is overcome by calculating both the quotient (DIV) and remainder (REM) in each basic block that is inserted by the optimization and reusing the result values when a subsequent DIV or REM instruction uses the same operands. - Test cases check for the presents of the optimization when calculating either the quotient, remainder, or both. Patch by Tyler Nowicki! git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163150 91177308-0d34-0410-b5e6-96231b3b80d8