Since mem2reg isn't run at -O0, we get a ton of reloads from the stack,
for example, before, this code:
int foo(int x, int y, int z) {
return x+y+z;
}
used to compile into:
_foo: ## @foo
subq $12, %rsp
movl %edi, 8(%rsp)
movl %esi, 4(%rsp)
movl %edx, (%rsp)
movl 8(%rsp), %edx
movl 4(%rsp), %esi
addl %edx, %esi
movl (%rsp), %edx
addl %esi, %edx
movl %edx, %eax
addq $12, %rsp
ret
Now we produce:
_foo: ## @foo
subq $12, %rsp
movl %edi, 8(%rsp)
movl %esi, 4(%rsp)
movl %edx, (%rsp)
movl 8(%rsp), %edx
addl 4(%rsp), %edx ## Folded load
addl (%rsp), %edx ## Folded load
movl %edx, %eax
addq $12, %rsp
ret
Fewer instructions and less register use = faster compiles.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@113102 91177308-0d34-0410-b5e6-96231b3b80d8
constants, since they may not be emited near the other instructions
which get the same line, and this confuses debug info.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@108302 91177308-0d34-0410-b5e6-96231b3b80d8
- Check getBytesToPopOnReturn().
- Eschew ST0 and ST1 for return values.
- Fix the PIC base register initialization so that it doesn't ever
fail to end up the top of the entry block.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@108039 91177308-0d34-0410-b5e6-96231b3b80d8
U utils/TableGen/FastISelEmitter.cpp
--- Reverse-merging r107943 into '.':
U test/CodeGen/X86/fast-isel.ll
U test/CodeGen/X86/fast-isel-loads.ll
U include/llvm/Target/TargetLowering.h
U include/llvm/Support/PassNameParser.h
U include/llvm/CodeGen/FunctionLoweringInfo.h
U include/llvm/CodeGen/CallingConvLower.h
U include/llvm/CodeGen/FastISel.h
U include/llvm/CodeGen/SelectionDAGISel.h
U lib/CodeGen/LLVMTargetMachine.cpp
U lib/CodeGen/CallingConvLower.cpp
U lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
U lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
U lib/CodeGen/SelectionDAG/FastISel.cpp
U lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
U lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
U lib/CodeGen/SelectionDAG/InstrEmitter.cpp
U lib/CodeGen/SelectionDAG/TargetLowering.cpp
U lib/Target/XCore/XCoreISelLowering.cpp
U lib/Target/XCore/XCoreISelLowering.h
U lib/Target/X86/X86ISelLowering.cpp
U lib/Target/X86/X86FastISel.cpp
U lib/Target/X86/X86ISelLowering.h
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@107987 91177308-0d34-0410-b5e6-96231b3b80d8
around everywhere, and also give it an InsertPt member, to enable isel
to operate at an arbitrary position within a block, rather than just
appending to a block.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@107791 91177308-0d34-0410-b5e6-96231b3b80d8
instance, rather than pointers to all of FunctionLoweringInfo's
members.
This eliminates an NDEBUG ABI sensitivity.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@107789 91177308-0d34-0410-b5e6-96231b3b80d8
available in a register. This is pretty primitive, but it reduces the
number of instructions in common testcases by 4%.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@107380 91177308-0d34-0410-b5e6-96231b3b80d8
addresses a longstanding deficiency noted in many FIXMEs scattered
across all the targets.
This effectively moves the problem up one level, replacing eleven
FIXMEs in the targets with eight FIXMEs in CodeGen, plus one path
through FastISel where we actually supply a DebugLoc, fixing Radar
7421831.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106243 91177308-0d34-0410-b5e6-96231b3b80d8
in registers into a separate function to de-couple it from the
top-down-specific logic in getRegForValue.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@102975 91177308-0d34-0410-b5e6-96231b3b80d8
This involves temporarily hard wiring some parts to use the global context. This isn't ideal, but it's
the only way I could figure out to make this process vaguely incremental.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75445 91177308-0d34-0410-b5e6-96231b3b80d8
by inserting explicit zero extensions where necessary. Included
is a testcase where SelectionDAG produces a virtual register
holding an i1 value which FastISel previously mistakenly assumed
to be zero-extended.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@66941 91177308-0d34-0410-b5e6-96231b3b80d8
and use it in x86 address mode folding. Also, make
getRegForValue return 0 for illegal types even if it has a
ValueMap for them, because Argument values are put in the
ValueMap. This fixes PR3181.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60696 91177308-0d34-0410-b5e6-96231b3b80d8
- Move the EH landing-pad code and adjust it so that it works
with FastISel as well as with SDISel.
- Add FastISel support for @llvm.eh.exception and
@llvm.eh.selector.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@57539 91177308-0d34-0410-b5e6-96231b3b80d8
expand to multiple basic blocks, in which case fast-isel
needs to informed of which block to use as it resumes
inserting instructions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@57040 91177308-0d34-0410-b5e6-96231b3b80d8
