From 0fe71e9bb19ff1781813184e41a8aaaae4dd2908 Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Thu, 21 Feb 2008 19:43:13 +0000 Subject: Treat clobber operands like early clobbers: if we have any, we force sdisel to do all regalloc for an asm. This leads to gross but correct codegen. This fixes the rest of PR2078. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47454 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'lib/CodeGen') diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp index def4f9a..e159c11 100644 --- a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp +++ b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp @@ -3467,6 +3467,17 @@ void AsmOperandInfo::ComputeConstraintToUse(const TargetLowering &TLI) { } +/// GetRegistersForValue - Assign registers (virtual or physical) for the +/// specified operand. We prefer to assign virtual registers, to allow the +/// register allocator handle the assignment process. However, if the asm uses +/// features that we can't model on machineinstrs, we have SDISel do the +/// allocation. This produces generally horrible, but correct, code. +/// +/// OpInfo describes the operand. +/// HasEarlyClobber is true if there are any early clobber constraints (=&r) +/// or any explicitly clobbered registers. +/// Input and OutputRegs are the set of already allocated physical registers. +/// void SelectionDAGLowering:: GetRegistersForValue(AsmOperandInfo &OpInfo, bool HasEarlyClobber, std::set &OutputRegs, @@ -3723,6 +3734,11 @@ void SelectionDAGLowering::visitInlineAsm(CallSite CS) { // Keep track of whether we see an earlyclobber. SawEarlyClobber |= OpInfo.isEarlyClobber; + // If we see a clobber of a register, it is an early clobber. + if (OpInfo.Type == InlineAsm::isClobber && + OpInfo.ConstraintType == TargetLowering::C_Register) + SawEarlyClobber = true; + // If this is a memory input, and if the operand is not indirect, do what we // need to to provide an address for the memory input. if (OpInfo.ConstraintType == TargetLowering::C_Memory && -- cgit v1.1