diff options
| author | Chris Lattner <sabre@nondot.org> | 2004-05-04 15:47:14 +0000 |
|---|---|---|
| committer | Chris Lattner <sabre@nondot.org> | 2004-05-04 15:47:14 +0000 |
| commit | 9eb9b8ecb9c02244fa5c7b96812c45239d6ffb85 (patch) | |
| tree | 7049c3162525713c73d881a5bb2771b845a8bbd4 | |
| parent | 32ed46b36e1457b0b978cd5434cce3bdae4c914b (diff) | |
Improve code generated for integer multiplications by 2,3,5,9
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13342 91177308-0d34-0410-b5e6-96231b3b80d8
| -rw-r--r-- | lib/Target/X86/InstSelectSimple.cpp | 18 | ||||
| -rw-r--r-- | lib/Target/X86/X86ISelSimple.cpp | 18 |
2 files changed, 32 insertions, 4 deletions
diff --git a/lib/Target/X86/InstSelectSimple.cpp b/lib/Target/X86/InstSelectSimple.cpp index a9befc6069..bf9846616e 100644 --- a/lib/Target/X86/InstSelectSimple.cpp +++ b/lib/Target/X86/InstSelectSimple.cpp @@ -2196,15 +2196,29 @@ void ISel::doMultiplyConst(MachineBasicBlock *MBB, unsigned op0Reg, unsigned ConstRHS) { static const unsigned MOVrrTab[] = {X86::MOV8rr, X86::MOV16rr, X86::MOV32rr}; static const unsigned MOVriTab[] = {X86::MOV8ri, X86::MOV16ri, X86::MOV32ri}; + static const unsigned ADDrrTab[] = {X86::ADD8rr, X86::ADD16rr, X86::ADD32rr}; unsigned Class = getClass(DestTy); - if (ConstRHS == 0) { + // Handle special cases here. + switch (ConstRHS) { + case 0: BuildMI(*MBB, IP, MOVriTab[Class], 1, DestReg).addImm(0); return; - } else if (ConstRHS == 1) { + case 1: BuildMI(*MBB, IP, MOVrrTab[Class], 1, DestReg).addReg(op0Reg); return; + case 2: + BuildMI(*MBB, IP, ADDrrTab[Class], 1,DestReg).addReg(op0Reg).addReg(op0Reg); + return; + case 3: + case 5: + case 9: + if (Class == cInt) { + addFullAddress(BuildMI(*MBB, IP, X86::LEA32r, 5, DestReg), + op0Reg, ConstRHS-1, op0Reg, 0); + return; + } } // If the element size is exactly a power of 2, use a shift to get it. diff --git a/lib/Target/X86/X86ISelSimple.cpp b/lib/Target/X86/X86ISelSimple.cpp index a9befc6069..bf9846616e 100644 --- a/lib/Target/X86/X86ISelSimple.cpp +++ b/lib/Target/X86/X86ISelSimple.cpp @@ -2196,15 +2196,29 @@ void ISel::doMultiplyConst(MachineBasicBlock *MBB, unsigned op0Reg, unsigned ConstRHS) { static const unsigned MOVrrTab[] = {X86::MOV8rr, X86::MOV16rr, X86::MOV32rr}; static const unsigned MOVriTab[] = {X86::MOV8ri, X86::MOV16ri, X86::MOV32ri}; + static const unsigned ADDrrTab[] = {X86::ADD8rr, X86::ADD16rr, X86::ADD32rr}; unsigned Class = getClass(DestTy); - if (ConstRHS == 0) { + // Handle special cases here. + switch (ConstRHS) { + case 0: BuildMI(*MBB, IP, MOVriTab[Class], 1, DestReg).addImm(0); return; - } else if (ConstRHS == 1) { + case 1: BuildMI(*MBB, IP, MOVrrTab[Class], 1, DestReg).addReg(op0Reg); return; + case 2: + BuildMI(*MBB, IP, ADDrrTab[Class], 1,DestReg).addReg(op0Reg).addReg(op0Reg); + return; + case 3: + case 5: + case 9: + if (Class == cInt) { + addFullAddress(BuildMI(*MBB, IP, X86::LEA32r, 5, DestReg), + op0Reg, ConstRHS-1, op0Reg, 0); + return; + } } // If the element size is exactly a power of 2, use a shift to get it. |