From 3988226d5d4559c6518793c6aeb25b12c89dac47 Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Fri, 4 Jan 2008 07:36:53 +0000 Subject: Add a really quick hack at a machine code sinking pass, enabled with --enable-sinking. 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 --- lib/CodeGen/LLVMTargetMachine.cpp | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'lib/CodeGen/LLVMTargetMachine.cpp') diff --git a/lib/CodeGen/LLVMTargetMachine.cpp b/lib/CodeGen/LLVMTargetMachine.cpp index 05284347f0..6a8e775e6b 100644 --- a/lib/CodeGen/LLVMTargetMachine.cpp +++ b/lib/CodeGen/LLVMTargetMachine.cpp @@ -29,6 +29,12 @@ static cl::opt PrintISelInput("print-isel-input", cl::Hidden, static cl::opt PrintEmittedAsm("print-emitted-asm", cl::Hidden, cl::desc("Dump emitter generated instructions as assembly")); +// Hidden options to help debugging +static cl::opt +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()); -- cgit v1.2.3