mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-08-30 05:29:47 +00:00
I noticed this in the code compiled for a routine using std::map, which produced this code: %25 = tail call i32 @memcmp(i8* %24, i8* %23, i32 6) nounwind readonly %.lobit.i = lshr i32 %25, 31 ; <i32> [#uses=1] %tmp.i = trunc i32 %.lobit.i to i8 ; <i8> [#uses=1] %toBool = icmp eq i8 %tmp.i, 0 ; <i1> [#uses=1] br i1 %toBool, label %bb3, label %bb4 which compiled to: call L_memcmp$stub shrl $31, %eax testb %al, %al jne LBB1_11 ## with this change, we compile it to: call L_memcmp$stub testl %eax, %eax js LBB1_11 This triggers all the time in common code, with patters like this: %169 = and i32 %ply, 1 ; <i32> [#uses=1] %170 = trunc i32 %169 to i8 ; <i8> [#uses=1] %toBool = icmp ne i8 %170, 0 ; <i1> [#uses=1] %7 = lshr i32 %6, 24 ; <i32> [#uses=1] %9 = trunc i32 %7 to i8 ; <i8> [#uses=1] %10 = icmp ne i8 %9, 0 ; <i1> [#uses=1] etc git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61985 91177308-0d34-0410-b5e6-96231b3b80d8 |
||
---|---|---|
.. | ||
ADCE.cpp | ||
BasicBlockPlacement.cpp | ||
CMakeLists.txt | ||
CodeGenPrepare.cpp | ||
CondPropagate.cpp | ||
ConstantProp.cpp | ||
DCE.cpp | ||
DeadStoreElimination.cpp | ||
GVN.cpp | ||
GVNPRE.cpp | ||
IndVarSimplify.cpp | ||
InstructionCombining.cpp | ||
JumpThreading.cpp | ||
LICM.cpp | ||
LoopDeletion.cpp | ||
LoopIndexSplit.cpp | ||
LoopRotation.cpp | ||
LoopStrengthReduce.cpp | ||
LoopUnroll.cpp | ||
LoopUnswitch.cpp | ||
Makefile | ||
MemCpyOptimizer.cpp | ||
PredicateSimplifier.cpp | ||
Reassociate.cpp | ||
Reg2Mem.cpp | ||
Scalar.cpp | ||
ScalarReplAggregates.cpp | ||
SCCP.cpp | ||
SimplifyCFGPass.cpp | ||
SimplifyHalfPowrLibCalls.cpp | ||
SimplifyLibCalls.cpp | ||
TailDuplication.cpp | ||
TailRecursionElimination.cpp |