6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-11-23 00:20:25 +00:00
Code Issues Projects Releases Wiki Activity

Add a really quick hack at a machine code sinking pass, enabled with --enable-sinking.

Browse Source 
It is missing validity checks, so it is known broken.  However, it is powerful enough
to compile this contrived code:

void test1(int C, double A, double B, double *P) {
  double Tmp = A*A+B*B;
  *P = C ? Tmp : A;
}

into:

_test1:
	movsd	8(%esp), %xmm0
	cmpl	$0, 4(%esp)
	je	LBB1_2	# entry
LBB1_1:	# entry
	movsd	16(%esp), %xmm1
	mulsd	%xmm1, %xmm1
	mulsd	%xmm0, %xmm0
	addsd	%xmm1, %xmm0
LBB1_2:	# entry
	movl	24(%esp), %eax
	movsd	%xmm0, (%eax)
	ret

instead of:

_test1:
	movsd	16(%esp), %xmm0
	mulsd	%xmm0, %xmm0
	movsd	8(%esp), %xmm1
	movapd	%xmm1, %xmm2
	mulsd	%xmm2, %xmm2
	addsd	%xmm0, %xmm2
	cmpl	$0, 4(%esp)
	je	LBB1_2	# entry
LBB1_1:	# entry
	movapd	%xmm2, %xmm1
LBB1_2:	# entry
	movl	24(%esp), %eax
	movsd	%xmm1, (%eax)
	ret

woo.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45570 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner
2008-01-04 07:36:53 +00:00
parent ac69582664
commit c4ce73f666
3 changed files with 219 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

9
lib/CodeGen/LLVMTargetMachine.cpp
View File

@@ -29,6 +29,12 @@ static cl::opt<bool> PrintISelInput("print-isel-input", cl::Hidden,
static cl::opt<bool> PrintEmittedAsm("print-emitted-asm", cl::Hidden,
cl::desc("Dump emitter generated instructions as assembly"));
// Hidden options to help debugging
static cl::opt<bool>
EnableSinking("enable-sinking", cl::init(false), cl::Hidden,
cl::desc("Perform sinking on machine code"));
FileModel::Model
LLVMTargetMachine::addPassesToEmitFile(FunctionPassManager &PM,
std::ostream &Out,
@@ -68,6 +74,9 @@ LLVMTargetMachine::addPassesToEmitFile(FunctionPassManager &PM,
PM.add(createMachineFunctionPrinterPass(cerr));
PM.add(createMachineLICMPass());
if (EnableSinking)
PM.add(createMachineSinkingPass());
// Perform register allocation to convert to a concrete x86 representation
PM.add(createRegisterAllocator());