diff options
| -rw-r--r-- | 013direct_addressing.cc | 4 | ||||
| -rw-r--r-- | 015immediate_addressing.cc | 39 | ||||
| -rw-r--r-- | 033check_operands.cc | 5 | ||||
| -rwxr-xr-x | apps/ex14 | bin | 0 -> 213 bytes | |||
| -rw-r--r-- | apps/ex14.subx | 26 |
5 files changed, 71 insertions, 3 deletions
diff --git a/013direct_addressing.cc b/013direct_addressing.cc index 729b4d08..2450e54c 100644 --- a/013direct_addressing.cc +++ b/013direct_addressing.cc @@ -321,10 +321,8 @@ case 0xaf: { // multiply r32 by r/m32 trace(Callstack_depth+1, "run") << "multiply " << rname(arg1) << " by r/m32" << end(); const int32_t* arg2 = effective_address(modrm); int32_t result = Reg[arg1].i * (*arg2); - SF = (Reg[arg1].i < 0); - ZF = (Reg[arg1].i == 0); int64_t full_result = static_cast<int64_t>(Reg[arg1].i) * (*arg2); - OF = (Reg[arg1].i != full_result); + OF = (result != full_result); CF = OF; trace(Callstack_depth+1, "run") << "SF=" << SF << "; ZF=" << ZF << "; CF=" << CF << "; OF=" << OF << end(); Reg[arg1].i = result; diff --git a/015immediate_addressing.cc b/015immediate_addressing.cc index a2923b7a..c1363ae1 100644 --- a/015immediate_addressing.cc +++ b/015immediate_addressing.cc @@ -1270,3 +1270,42 @@ case 0x68: { trace(Callstack_depth+1, "run") << "contents at ESP: 0x" << HEXWORD << read_mem_u32(Reg[ESP].u) << end(); break; } + +//:: multiply + +:(before "End Initialize Op Names") +put_new(Name, "69", "multiply rm32 by imm32 and store result in r32"); + +:(code) +void test_multiply_imm32() { + Reg[EAX].i = 2; + Reg[EBX].i = 3; + run( + "== code 0x1\n" + // op ModR/M SIB displacement immediate + " 69 c3 04 00 00 00 \n" // EAX = EBX * 4 + // ModR/M in binary: 11 (direct) 000 (dest EAX) 011 (src EBX) + ); + CHECK_TRACE_CONTENTS( + "run: multiply r/m32 by 0x00000004 and store result in EAX\n" + "run: r/m32 is EBX\n" + "run: storing 0x0000000c\n" + ); +} + +:(before "End Single-Byte Opcodes") +case 0x69: { + const uint8_t modrm = next(); + const uint8_t rdest = (modrm>>3)&0x7; + const int32_t val = next32(); + trace(Callstack_depth+1, "run") << "multiply r/m32 by 0x" << HEXWORD << val << " and store result in " << rname(rdest) << end(); + const int32_t* signed_arg1 = effective_address(modrm); + int32_t result = *signed_arg1 * val; + int64_t full_result = static_cast<int64_t>(*signed_arg1) * val; + OF = (result != full_result); + CF = OF; + trace(Callstack_depth+1, "run") << "SF=" << SF << "; ZF=" << ZF << "; CF=" << CF << "; OF=" << OF << end(); + Reg[rdest].i = result; + trace(Callstack_depth+1, "run") << "storing 0x" << HEXWORD << Reg[rdest].i << end(); + break; +} diff --git a/033check_operands.cc b/033check_operands.cc index 04492986..28a7458e 100644 --- a/033check_operands.cc +++ b/033check_operands.cc @@ -246,6 +246,11 @@ void init_permitted_operands() { put(Permitted_operands, "81", 0x43); // combine put(Permitted_operands, "c7", 0x43); // copy + //// Class Q: op, ModR/M and imm32 + // imm32 imm8 disp32 |disp16 disp8 subop modrm + // 1 0 0 |0 0 0 1 + put(Permitted_operands, "69", 0x41); // multiply + // End Init Permitted Operands } diff --git a/apps/ex14 b/apps/ex14 new file mode 100755 index 00000000..b2792177 --- /dev/null +++ b/apps/ex14 Binary files differdiff --git a/apps/ex14.subx b/apps/ex14.subx new file mode 100644 index 00000000..74dd3809 --- /dev/null +++ b/apps/ex14.subx @@ -0,0 +1,26 @@ +# Multiply 2 numbers. +# +# To run: +# $ ./bootstrap translate init.linux apps/ex14.subx -o apps/ex14 +# $ ./bootstrap run apps/ex14 +# Expected result: +# $ echo $? +# 6 + +== code +# instruction effective address register displacement immediate +# . op subop mod rm32 base index scale r32 +# . 1-3 bytes 3 bits 2 bits 3 bits 3 bits 3 bits 2 bits 2 bits 0/1/2/4 bytes 0/1/2/4 bytes + +Entry: + b8/copy-to-eax 1/imm32 + b9/copy-to-ecx 2/imm32 + bb/copy-to-ebx 3/imm32 + + 69/multiply 3/mod/direct 1/rm32/ecx . . . 3/r32/ebx 3/imm32 # ebx = ecx * 3 + +$exit: + # exit(ebx) + e8/call syscall_exit/disp32 + +# . . vim:nowrap:textwidth=0 |