+ // Table of which combinations can be emitted as a single instruction,
+ // and which will require two.
+ static const uint8_t isSingleInstrTbl[3][2][2][2] = {
+ // ARM Thumb
+ // !hasV6Ops hasV6Ops !hasV6Ops hasV6Ops
+ // ext: s z s z s z s z
+ /* 1 */ { { { 0, 1 }, { 0, 1 } }, { { 0, 0 }, { 0, 1 } } },
+ /* 8 */ { { { 0, 1 }, { 1, 1 } }, { { 0, 0 }, { 1, 1 } } },
+ /* 16 */ { { { 0, 0 }, { 1, 1 } }, { { 0, 0 }, { 1, 1 } } }
+ };
+
+ // Target registers for:
+ // - For ARM can never be PC.
+ // - For 16-bit Thumb are restricted to lower 8 registers.
+ // - For 32-bit Thumb are restricted to non-SP and non-PC.
+ static const TargetRegisterClass *RCTbl[2][2] = {
+ // Instructions: Two Single
+ /* ARM */ { &ARM::GPRnopcRegClass, &ARM::GPRnopcRegClass },
+ /* Thumb */ { &ARM::tGPRRegClass, &ARM::rGPRRegClass }
+ };
+
+ // Table governing the instruction(s) to be emitted.
+ static const struct InstructionTable {
+ uint32_t Opc : 16;
+ uint32_t hasS : 1; // Some instructions have an S bit, always set it to 0.
+ uint32_t Shift : 7; // For shift operand addressing mode, used by MOVsi.
+ uint32_t Imm : 8; // All instructions have either a shift or a mask.
+ } IT[2][2][3][2] = {
+ { // Two instructions (first is left shift, second is in this table).
+ { // ARM Opc S Shift Imm
+ /* 1 bit sext */ { { ARM::MOVsi , 1, ARM_AM::asr , 31 },
+ /* 1 bit zext */ { ARM::MOVsi , 1, ARM_AM::lsr , 31 } },
+ /* 8 bit sext */ { { ARM::MOVsi , 1, ARM_AM::asr , 24 },
+ /* 8 bit zext */ { ARM::MOVsi , 1, ARM_AM::lsr , 24 } },
+ /* 16 bit sext */ { { ARM::MOVsi , 1, ARM_AM::asr , 16 },
+ /* 16 bit zext */ { ARM::MOVsi , 1, ARM_AM::lsr , 16 } }
+ },
+ { // Thumb Opc S Shift Imm
+ /* 1 bit sext */ { { ARM::tASRri , 0, ARM_AM::no_shift, 31 },
+ /* 1 bit zext */ { ARM::tLSRri , 0, ARM_AM::no_shift, 31 } },
+ /* 8 bit sext */ { { ARM::tASRri , 0, ARM_AM::no_shift, 24 },
+ /* 8 bit zext */ { ARM::tLSRri , 0, ARM_AM::no_shift, 24 } },
+ /* 16 bit sext */ { { ARM::tASRri , 0, ARM_AM::no_shift, 16 },
+ /* 16 bit zext */ { ARM::tLSRri , 0, ARM_AM::no_shift, 16 } }
+ }
+ },
+ { // Single instruction.
+ { // ARM Opc S Shift Imm
+ /* 1 bit sext */ { { ARM::KILL , 0, ARM_AM::no_shift, 0 },
+ /* 1 bit zext */ { ARM::ANDri , 1, ARM_AM::no_shift, 1 } },
+ /* 8 bit sext */ { { ARM::SXTB , 0, ARM_AM::no_shift, 0 },
+ /* 8 bit zext */ { ARM::ANDri , 1, ARM_AM::no_shift, 255 } },
+ /* 16 bit sext */ { { ARM::SXTH , 0, ARM_AM::no_shift, 0 },
+ /* 16 bit zext */ { ARM::UXTH , 0, ARM_AM::no_shift, 0 } }
+ },
+ { // Thumb Opc S Shift Imm
+ /* 1 bit sext */ { { ARM::KILL , 0, ARM_AM::no_shift, 0 },
+ /* 1 bit zext */ { ARM::t2ANDri, 1, ARM_AM::no_shift, 1 } },
+ /* 8 bit sext */ { { ARM::t2SXTB , 0, ARM_AM::no_shift, 0 },
+ /* 8 bit zext */ { ARM::t2ANDri, 1, ARM_AM::no_shift, 255 } },
+ /* 16 bit sext */ { { ARM::t2SXTH , 0, ARM_AM::no_shift, 0 },
+ /* 16 bit zext */ { ARM::t2UXTH , 0, ARM_AM::no_shift, 0 } }
+ }