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One more instruction where I forgot to update the carry flag.
This commit is contained in:
Kartik Agaram 2019-05-15 00:44:59 -07:00
parent a5e7292d4d
commit 6376008f9f
1 changed files with 68 additions and 11 deletions
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79
subx/015immediate_addressing.cc
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@ -1012,27 +1012,84 @@ case 7: {
ZF = (tmp1 == 0);
const int64_t tmp2 = static_cast<int64_t>(*signed_arg1) - signed_arg2;
OF = (tmp1 != tmp2);
const uint32_t unsigned_arg1 = static_cast<uint32_t>(*signed_arg1);
const uint32_t unsigned_arg2 = static_cast<uint32_t>(signed_arg2);
const uint32_t tmp3 = unsigned_arg1 - unsigned_arg2;
const uint64_t tmp4 = static_cast<uint64_t>(unsigned_arg1) - unsigned_arg2;
CF = (tmp3 != tmp4);
trace(Callstack_depth+1, "run") << "SF=" << SF << "; ZF=" << ZF << "; CF=" << CF << "; OF=" << OF << end();
break;
}
:(code)
void test_compare_imm32_with_r32_lesser() {
Reg[EBX].i = 0x0d0c0b07;
void test_compare_rm32_with_imm32_lesser_unsigned_and_signed() {
Reg[EAX].i = 0x0a0b0c07;
run(
"== 0x1\n" // code segment
// op ModR/M SIB displacement immediate
" 81 fb 0a 0b 0c 0d \n" // compare 0x0d0c0b0a with EBX
// ModR/M in binary: 11 (direct mode) 111 (subop compare) 011 (dest EBX)
" 81 f8 0d 0c 0b 0a \n" // compare EAX with imm32
// ModR/M in binary: 11 (direct mode) 111 (subop compare) 000 (dest EAX)
);
CHECK_TRACE_CONTENTS(
"run: combine imm32 with r/m32\n"
"run: r/m32 is EBX\n"
"run: imm32 is 0x0d0c0b0a\n"
"run: r/m32 is EAX\n"
"run: imm32 is 0x0a0b0c0d\n"
"run: subop compare\n"
"run: SF=1; ZF=0; CF=1; OF=0\n"
);
}
void test_compare_rm32_with_imm32_lesser_unsigned_and_signed_due_to_overflow() {
Reg[EAX].i = 0x7fffffff; // largest positive signed integer
run(
"== 0x1\n" // code segment
// op ModR/M SIB displacement immediate
" 81 f8 00 00 00 80\n" // compare EAX with smallest negative signed integer
// ModR/M in binary: 11 (direct mode) 111 (subop compare) 000 (dest EAX)
);
CHECK_TRACE_CONTENTS(
"run: combine imm32 with r/m32\n"
"run: r/m32 is EAX\n"
"run: imm32 is 0x80000000\n"
"run: subop compare\n"
"run: SF=1; ZF=0; CF=1; OF=1\n"
);
}
void test_compare_rm32_with_imm32_lesser_signed() {
Reg[EAX].i = 0xffffffff; // -1
run(
"== 0x1\n" // code segment
// op ModR/M SIB displacement immediate
" 81 f8 01 00 00 00\n" // compare EAX with 1
// ModR/M in binary: 11 (direct mode) 111 (subop compare) 000 (dest EAX)
);
CHECK_TRACE_CONTENTS(
"run: combine imm32 with r/m32\n"
"run: r/m32 is EAX\n"
"run: imm32 is 0x00000001\n"
"run: subop compare\n"
"run: SF=1; ZF=0; CF=0; OF=0\n"
);
}
void test_compare_rm32_with_imm32_lesser_unsigned() {
Reg[EAX].i = 0x00000001; // 1
run(
"== 0x1\n" // code segment
// op ModR/M SIB displacement immediate
" 81 f8 ff ff ff ff\n" // compare EAX with -1
// ModR/M in binary: 11 (direct mode) 111 (subop compare) 000 (dest EAX)
);
CHECK_TRACE_CONTENTS(
"run: combine imm32 with r/m32\n"
"run: r/m32 is EAX\n"
"run: imm32 is 0xffffffff\n"
"run: subop compare\n"
"run: SF=0; ZF=0; CF=1; OF=0\n"
);
}
:(code)
void test_compare_imm32_with_r32_equal() {
Reg[EBX].i = 0x0d0c0b0a;
@ -1071,20 +1128,20 @@ void test_compare_imm32_with_mem_at_r32_greater() {
:(code)
void test_compare_imm32_with_mem_at_r32_lesser() {
Reg[EBX].i = 0x2000;
Reg[EAX].i = 0x2000;
run(
"== 0x1\n" // code segment
// op ModR/M SIB displacement immediate
" 81 3b 0a 0b 0c 0d \n" // compare 0x0d0c0b0a with *EBX
// ModR/M in binary: 00 (indirect mode) 111 (subop compare) 011 (dest EBX)
" 81 38 0a 0b 0c 0d \n" // compare 0x0d0c0b0a with *EAX
// ModR/M in binary: 00 (indirect mode) 111 (subop compare) 000 (dest EAX)
"== 0x2000\n" // data segment
"07 0b 0c 0d\n" // 0x0d0c0b07
);
CHECK_TRACE_CONTENTS(
"run: combine imm32 with r/m32\n"
"run: effective address is 0x00002000 (EBX)\n"
"run: effective address is 0x00002000 (EAX)\n"
"run: imm32 is 0x0d0c0b0a\n"
"run: SF=1; ZF=0; CF=0; OF=0\n"
"run: SF=1; ZF=0; CF=1; OF=0\n"
);
}