diff options
| -rw-r--r-- | subx/015immediate_addressing.cc | 47 |
1 files changed, 46 insertions, 1 deletions
diff --git a/subx/015immediate_addressing.cc b/subx/015immediate_addressing.cc index 7c0da1a0..959482cb 100644 --- a/subx/015immediate_addressing.cc +++ b/subx/015immediate_addressing.cc @@ -244,9 +244,54 @@ case 0x2d: { // subtract imm32 from EAX break; } +:(code) +void test_subtract_imm32_from_EAX_signed_overflow() { + Reg[EAX].i = 0x80000000; // smallest negative signed integer + run( + "== 0x1\n" // code segment + // op ModR/M SIB displacement immediate + " 2d ff ff ff 7f \n" // subtract largest positive signed integer from EAX + // ModR/M in binary: 00 (indirect mode) 101 (subop subtract) 011 (dest EBX) + ); + CHECK_TRACE_CONTENTS( + "run: subtract imm32 0x7fffffff from EAX\n" + "run: SF=0; ZF=0; CF=0; OF=1\n" + "run: storing 0x00000001\n" + ); +} + +void test_subtract_imm32_from_EAX_unsigned_overflow() { + Reg[EAX].i = 0; + run( + "== 0x1\n" // code segment + // op ModR/M SIB displacement immediate + " 2d 01 00 00 00 \n" // subtract 1 from EAX + // ModR/M in binary: 00 (indirect mode) 101 (subop subtract) 011 (dest EBX) + ); + CHECK_TRACE_CONTENTS( + "run: subtract imm32 0x00000001 from EAX\n" + "run: SF=1; ZF=0; CF=1; OF=0\n" + "run: storing 0xffffffff\n" + ); +} + +void test_subtract_imm32_from_EAX_signed_and_unsigned_overflow() { + Reg[EAX].i = 0; + run( + "== 0x1\n" // code segment + // op ModR/M SIB displacement immediate + " 2d 00 00 00 80 \n" // subtract smallest negative signed integer from EAX + // ModR/M in binary: 00 (indirect mode) 101 (subop subtract) 011 (dest EBX) + ); + CHECK_TRACE_CONTENTS( + "run: subtract imm32 0x80000000 from EAX\n" + "run: SF=1; ZF=0; CF=1; OF=1\n" + "run: storing 0x80000000\n" + ); +} + //: -:(code) void test_subtract_imm32_from_mem_at_r32() { Reg[EBX].i = 0x2000; run( |