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Diffstat (limited to 'docs/re/test_v_cmp.txt')
| -rw-r--r-- | docs/re/test_v_cmp.txt | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/docs/re/test_v_cmp.txt b/docs/re/test_v_cmp.txt new file mode 100644 index 0000000..5a0c5af --- /dev/null +++ b/docs/re/test_v_cmp.txt @@ -0,0 +1,14 @@ +CMP subtracts operands and sets internal flags. Among these, it sets the +zero flag if the difference is zero (operands are equal). + +TEST sets the zero flag (ZF) when the result of the AND operation is zero. If +the two operands are equal, their bitwise AND is zero only when the operands +themselves are zero. TEST also sets the sign flag (SF) when the most +significant bit is set in the result, and the parity flag (PF) when the number +of set bits is even. + +JE (alias of JZ) tests the zero flag and jumps if it is set. This makes: +test eax, eax +je 0x1234 +equivalent to the C statement: +if (eax == 0) |