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Fix a (harmless) but where vregs were added to the used reg lists for 

inline asms.

Fix PR2078 by marking aliases of registers used when a register is 
marked used.  This prevents EAX from being allocated when AX is listed
in the clobber set for the asm.

llvm-svn: 47426
This commit is contained in:
Chris Lattner 2008-02-21 04:55:52 +00:00
parent ad582fc34b
commit 83c93d5afd
2 changed files with 41 additions and 9 deletions
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35
llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
View File

@ -3347,12 +3347,29 @@ struct AsmOperandInfo : public InlineAsm::ConstraintInfo {
/// busy in OutputRegs/InputRegs.
void MarkAllocatedRegs(bool isOutReg, bool isInReg,
std::set<unsigned> &OutputRegs,
std::set<unsigned> &InputRegs) const {
if (isOutReg)
OutputRegs.insert(AssignedRegs.Regs.begin(), AssignedRegs.Regs.end());
if (isInReg)
InputRegs.insert(AssignedRegs.Regs.begin(), AssignedRegs.Regs.end());
}
std::set<unsigned> &InputRegs,
const TargetRegisterInfo &TRI) const {
if (isOutReg) {
for (unsigned i = 0, e = AssignedRegs.Regs.size(); i != e; ++i)
MarkRegAndAliases(AssignedRegs.Regs[i], OutputRegs, TRI);
}
if (isInReg) {
for (unsigned i = 0, e = AssignedRegs.Regs.size(); i != e; ++i)
MarkRegAndAliases(AssignedRegs.Regs[i], InputRegs, TRI);
}
}
private:
/// MarkRegAndAliases - Mark the specified register and all aliases in the
/// specified set.
static void MarkRegAndAliases(unsigned Reg, std::set<unsigned> &Regs,
const TargetRegisterInfo &TRI) {
assert(TargetRegisterInfo::isPhysicalRegister(Reg) && "Isn't a physreg");
Regs.insert(Reg);
if (const unsigned *Aliases = TRI.getAliasSet(Reg))
for (; *Aliases; ++Aliases)
Regs.insert(*Aliases);
}
};
} // end anon namespace.
@ -3491,7 +3508,8 @@ GetRegistersForValue(AsmOperandInfo &OpInfo, bool HasEarlyClobber,
}
}
OpInfo.AssignedRegs = RegsForValue(Regs, RegVT, ValueVT);
OpInfo.MarkAllocatedRegs(isOutReg, isInReg, OutputRegs, InputRegs);
const TargetRegisterInfo *TRI = DAG.getTarget().getRegisterInfo();
OpInfo.MarkAllocatedRegs(isOutReg, isInReg, OutputRegs, InputRegs, *TRI);
return;
}
@ -3519,7 +3537,6 @@ GetRegistersForValue(AsmOperandInfo &OpInfo, bool HasEarlyClobber,
Regs.push_back(RegInfo.createVirtualRegister(PhysReg.second));
OpInfo.AssignedRegs = RegsForValue(Regs, RegVT, ValueVT);
OpInfo.MarkAllocatedRegs(isOutReg, isInReg, OutputRegs, InputRegs);
return;
}
@ -3571,7 +3588,7 @@ GetRegistersForValue(AsmOperandInfo &OpInfo, bool HasEarlyClobber,
OpInfo.AssignedRegs = RegsForValue(Regs, *RC->vt_begin(),
OpInfo.ConstraintVT);
OpInfo.MarkAllocatedRegs(isOutReg, isInReg, OutputRegs, InputRegs);
OpInfo.MarkAllocatedRegs(isOutReg, isInReg, OutputRegs, InputRegs, *TRI);
return;
}
}

15
llvm/test/CodeGen/X86/2008-02-20-InlineAsmClobber.ll Normal file
View File

@ -0,0 +1,15 @@
; RUN: llvm-as < %s | llc | grep {%ecx %ecx}
; PR2078
; The clobber list says that "ax" is clobbered. Make sure that eax isn't
; allocated to the input/output register.
target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"
target triple = "i386-apple-darwin8"
@pixels = weak global i32 0 ; <i32*> [#uses=2]
define void @test() nounwind {
entry:
%tmp = load i32* @pixels, align 4 ; <i32> [#uses=1]
%tmp1 = tail call i32 asm sideeffect "$0 $1", "=r,0,~{dirflag},~{fpsr},~{flags},~{ax}"( i32 %tmp ) nounwind ; <i32> [#uses=1]
store i32 %tmp1, i32* @pixels, align 4
ret void
}