|  | //===- X86InstrExtension.td - Sign and Zero Extensions -----*- tablegen -*-===// | 
|  | // | 
|  | //                     The LLVM Compiler Infrastructure | 
|  | // | 
|  | // This file is distributed under the University of Illinois Open Source | 
|  | // License. See LICENSE.TXT for details. | 
|  | // | 
|  | //===----------------------------------------------------------------------===// | 
|  | // | 
|  | // This file describes the sign and zero extension operations. | 
|  | // | 
|  | //===----------------------------------------------------------------------===// | 
|  |  | 
|  | let neverHasSideEffects = 1 in { | 
|  | let Defs = [AX], Uses = [AL] in | 
|  | def CBW : I<0x98, RawFrm, (outs), (ins), | 
|  | "{cbtw|cbw}", []>, OpSize;   // AX = signext(AL) | 
|  | let Defs = [EAX], Uses = [AX] in | 
|  | def CWDE : I<0x98, RawFrm, (outs), (ins), | 
|  | "{cwtl|cwde}", []>;   // EAX = signext(AX) | 
|  |  | 
|  | let Defs = [AX,DX], Uses = [AX] in | 
|  | def CWD : I<0x99, RawFrm, (outs), (ins), | 
|  | "{cwtd|cwd}", []>, OpSize; // DX:AX = signext(AX) | 
|  | let Defs = [EAX,EDX], Uses = [EAX] in | 
|  | def CDQ : I<0x99, RawFrm, (outs), (ins), | 
|  | "{cltd|cdq}", []>; // EDX:EAX = signext(EAX) | 
|  |  | 
|  |  | 
|  | let Defs = [RAX], Uses = [EAX] in | 
|  | def CDQE : RI<0x98, RawFrm, (outs), (ins), | 
|  | "{cltq|cdqe}", []>;     // RAX = signext(EAX) | 
|  |  | 
|  | let Defs = [RAX,RDX], Uses = [RAX] in | 
|  | def CQO  : RI<0x99, RawFrm, (outs), (ins), | 
|  | "{cqto|cqo}", []>; // RDX:RAX = signext(RAX) | 
|  | } | 
|  |  | 
|  |  | 
|  | // Sign/Zero extenders | 
|  | def MOVSX16rr8 : I<0xBE, MRMSrcReg, (outs GR16:$dst), (ins GR8:$src), | 
|  | "movs{bw|x}\t{$src, $dst|$dst, $src}", []>, TB, OpSize; | 
|  | def MOVSX16rm8 : I<0xBE, MRMSrcMem, (outs GR16:$dst), (ins i8mem:$src), | 
|  | "movs{bw|x}\t{$src, $dst|$dst, $src}", []>, TB, OpSize; | 
|  | def MOVSX32rr8 : I<0xBE, MRMSrcReg, (outs GR32:$dst), (ins GR8:$src), | 
|  | "movs{bl|x}\t{$src, $dst|$dst, $src}", | 
|  | [(set GR32:$dst, (sext GR8:$src))]>, TB; | 
|  | def MOVSX32rm8 : I<0xBE, MRMSrcMem, (outs GR32:$dst), (ins i8mem :$src), | 
|  | "movs{bl|x}\t{$src, $dst|$dst, $src}", | 
|  | [(set GR32:$dst, (sextloadi32i8 addr:$src))]>, TB; | 
|  | def MOVSX32rr16: I<0xBF, MRMSrcReg, (outs GR32:$dst), (ins GR16:$src), | 
|  | "movs{wl|x}\t{$src, $dst|$dst, $src}", | 
|  | [(set GR32:$dst, (sext GR16:$src))]>, TB; | 
|  | def MOVSX32rm16: I<0xBF, MRMSrcMem, (outs GR32:$dst), (ins i16mem:$src), | 
|  | "movs{wl|x}\t{$src, $dst|$dst, $src}", | 
|  | [(set GR32:$dst, (sextloadi32i16 addr:$src))]>, TB; | 
|  |  | 
|  | def MOVZX16rr8 : I<0xB6, MRMSrcReg, (outs GR16:$dst), (ins GR8:$src), | 
|  | "movz{bw|x}\t{$src, $dst|$dst, $src}", []>, TB, OpSize; | 
|  | def MOVZX16rm8 : I<0xB6, MRMSrcMem, (outs GR16:$dst), (ins i8mem:$src), | 
|  | "movz{bw|x}\t{$src, $dst|$dst, $src}", []>, TB, OpSize; | 
|  | def MOVZX32rr8 : I<0xB6, MRMSrcReg, (outs GR32:$dst), (ins GR8 :$src), | 
|  | "movz{bl|x}\t{$src, $dst|$dst, $src}", | 
|  | [(set GR32:$dst, (zext GR8:$src))]>, TB; | 
|  | def MOVZX32rm8 : I<0xB6, MRMSrcMem, (outs GR32:$dst), (ins i8mem :$src), | 
|  | "movz{bl|x}\t{$src, $dst|$dst, $src}", | 
|  | [(set GR32:$dst, (zextloadi32i8 addr:$src))]>, TB; | 
|  | def MOVZX32rr16: I<0xB7, MRMSrcReg, (outs GR32:$dst), (ins GR16:$src), | 
|  | "movz{wl|x}\t{$src, $dst|$dst, $src}", | 
|  | [(set GR32:$dst, (zext GR16:$src))]>, TB; | 
|  | def MOVZX32rm16: I<0xB7, MRMSrcMem, (outs GR32:$dst), (ins i16mem:$src), | 
|  | "movz{wl|x}\t{$src, $dst|$dst, $src}", | 
|  | [(set GR32:$dst, (zextloadi32i16 addr:$src))]>, TB; | 
|  |  | 
|  | // These are the same as the regular MOVZX32rr8 and MOVZX32rm8 | 
|  | // except that they use GR32_NOREX for the output operand register class | 
|  | // instead of GR32. This allows them to operate on h registers on x86-64. | 
|  | def MOVZX32_NOREXrr8 : I<0xB6, MRMSrcReg, | 
|  | (outs GR32_NOREX:$dst), (ins GR8_NOREX:$src), | 
|  | "movz{bl|x}\t{$src, $dst|$dst, $src}", | 
|  | []>, TB; | 
|  | let mayLoad = 1 in | 
|  | def MOVZX32_NOREXrm8 : I<0xB6, MRMSrcMem, | 
|  | (outs GR32_NOREX:$dst), (ins i8mem_NOREX:$src), | 
|  | "movz{bl|x}\t{$src, $dst|$dst, $src}", | 
|  | []>, TB; | 
|  |  | 
|  | // MOVSX64rr8 always has a REX prefix and it has an 8-bit register | 
|  | // operand, which makes it a rare instruction with an 8-bit register | 
|  | // operand that can never access an h register. If support for h registers | 
|  | // were generalized, this would require a special register class. | 
|  | def MOVSX64rr8 : RI<0xBE, MRMSrcReg, (outs GR64:$dst), (ins GR8 :$src), | 
|  | "movs{bq|x}\t{$src, $dst|$dst, $src}", | 
|  | [(set GR64:$dst, (sext GR8:$src))]>, TB; | 
|  | def MOVSX64rm8 : RI<0xBE, MRMSrcMem, (outs GR64:$dst), (ins i8mem :$src), | 
|  | "movs{bq|x}\t{$src, $dst|$dst, $src}", | 
|  | [(set GR64:$dst, (sextloadi64i8 addr:$src))]>, TB; | 
|  | def MOVSX64rr16: RI<0xBF, MRMSrcReg, (outs GR64:$dst), (ins GR16:$src), | 
|  | "movs{wq|x}\t{$src, $dst|$dst, $src}", | 
|  | [(set GR64:$dst, (sext GR16:$src))]>, TB; | 
|  | def MOVSX64rm16: RI<0xBF, MRMSrcMem, (outs GR64:$dst), (ins i16mem:$src), | 
|  | "movs{wq|x}\t{$src, $dst|$dst, $src}", | 
|  | [(set GR64:$dst, (sextloadi64i16 addr:$src))]>, TB; | 
|  | def MOVSX64rr32: RI<0x63, MRMSrcReg, (outs GR64:$dst), (ins GR32:$src), | 
|  | "movs{lq|xd}\t{$src, $dst|$dst, $src}", | 
|  | [(set GR64:$dst, (sext GR32:$src))]>; | 
|  | def MOVSX64rm32: RI<0x63, MRMSrcMem, (outs GR64:$dst), (ins i32mem:$src), | 
|  | "movs{lq|xd}\t{$src, $dst|$dst, $src}", | 
|  | [(set GR64:$dst, (sextloadi64i32 addr:$src))]>; | 
|  |  | 
|  | // movzbq and movzwq encodings for the disassembler | 
|  | def MOVZX64rr8_Q : RI<0xB6, MRMSrcReg, (outs GR64:$dst), (ins GR8:$src), | 
|  | "movz{bq|x}\t{$src, $dst|$dst, $src}", []>, TB; | 
|  | def MOVZX64rm8_Q : RI<0xB6, MRMSrcMem, (outs GR64:$dst), (ins i8mem:$src), | 
|  | "movz{bq|x}\t{$src, $dst|$dst, $src}", []>, TB; | 
|  | def MOVZX64rr16_Q : RI<0xB7, MRMSrcReg, (outs GR64:$dst), (ins GR16:$src), | 
|  | "movz{wq|x}\t{$src, $dst|$dst, $src}", []>, TB; | 
|  | def MOVZX64rm16_Q : RI<0xB7, MRMSrcMem, (outs GR64:$dst), (ins i16mem:$src), | 
|  | "movz{wq|x}\t{$src, $dst|$dst, $src}", []>, TB; | 
|  |  | 
|  | // FIXME: These should be Pat patterns. | 
|  | let isCodeGenOnly = 1 in { | 
|  |  | 
|  | // Use movzbl instead of movzbq when the destination is a register; it's | 
|  | // equivalent due to implicit zero-extending, and it has a smaller encoding. | 
|  | def MOVZX64rr8 : I<0xB6, MRMSrcReg, (outs GR64:$dst), (ins GR8 :$src), | 
|  | "", [(set GR64:$dst, (zext GR8:$src))]>, TB; | 
|  | def MOVZX64rm8 : I<0xB6, MRMSrcMem, (outs GR64:$dst), (ins i8mem :$src), | 
|  | "", [(set GR64:$dst, (zextloadi64i8 addr:$src))]>, TB; | 
|  | // Use movzwl instead of movzwq when the destination is a register; it's | 
|  | // equivalent due to implicit zero-extending, and it has a smaller encoding. | 
|  | def MOVZX64rr16: I<0xB7, MRMSrcReg, (outs GR64:$dst), (ins GR16:$src), | 
|  | "", [(set GR64:$dst, (zext GR16:$src))]>, TB; | 
|  | def MOVZX64rm16: I<0xB7, MRMSrcMem, (outs GR64:$dst), (ins i16mem:$src), | 
|  | "", [(set GR64:$dst, (zextloadi64i16 addr:$src))]>, TB; | 
|  |  | 
|  | // There's no movzlq instruction, but movl can be used for this purpose, using | 
|  | // implicit zero-extension. The preferred way to do 32-bit-to-64-bit zero | 
|  | // extension on x86-64 is to use a SUBREG_TO_REG to utilize implicit | 
|  | // zero-extension, however this isn't possible when the 32-bit value is | 
|  | // defined by a truncate or is copied from something where the high bits aren't | 
|  | // necessarily all zero. In such cases, we fall back to these explicit zext | 
|  | // instructions. | 
|  | def MOVZX64rr32 : I<0x89, MRMDestReg, (outs GR64:$dst), (ins GR32:$src), | 
|  | "", [(set GR64:$dst, (zext GR32:$src))]>; | 
|  | def MOVZX64rm32 : I<0x8B, MRMSrcMem, (outs GR64:$dst), (ins i32mem:$src), | 
|  | "", [(set GR64:$dst, (zextloadi64i32 addr:$src))]>; | 
|  |  | 
|  |  | 
|  | } | 
|  |  |