diff options
| author | Dan Gohman <gohman@apple.com> | 2010-02-08 23:58:47 +0000 |
|---|---|---|
| committer | Dan Gohman <gohman@apple.com> | 2010-02-08 23:58:47 +0000 |
| commit | 036c130e90eb5c93b0dc0a70ad07b9343623c2a8 (patch) | |
| tree | 5f4861b1fc9be3031683bb2715d064c126d57fec | |
| parent | 8609fda0f7e4446de85f882755601ffcbd540324 (diff) | |
Document that MCExpr::Mod is actually remainder.
Document that MCExpr::Div, Mod, and the comparison operators are all
signed operators.
Document that the comparison operators' results are target-dependent.
Document that the behavior of shr is target-dependent.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95619 91177308-0d34-0410-b5e6-96231b3b80d8
| -rw-r--r-- | include/llvm/MC/MCExpr.h | 20 | ||||
| -rw-r--r-- | lib/MC/MCExpr.cpp | 4 |
2 files changed, 14 insertions, 10 deletions
diff --git a/include/llvm/MC/MCExpr.h b/include/llvm/MC/MCExpr.h index 04eeb6666a..afc90d910b 100644 --- a/include/llvm/MC/MCExpr.h +++ b/include/llvm/MC/MCExpr.h @@ -202,20 +202,24 @@ public: enum Opcode { Add, ///< Addition. And, ///< Bitwise and. - Div, ///< Division. + Div, ///< Signed division. EQ, ///< Equality comparison. - GT, ///< Greater than comparison. - GTE, ///< Greater than or equal comparison. + GT, ///< Signed greater than comparison (result is either 0 or some + ///< target-specific non-zero value) + GTE, ///< Signed greater than or equal comparison (result is either 0 or + ///< some target-specific non-zero value). LAnd, ///< Logical and. LOr, ///< Logical or. - LT, ///< Less than comparison. - LTE, ///< Less than or equal comparison. - Mod, ///< Modulus. + LT, ///< Signed less than comparison (result is either 0 or + ///< some target-specific non-zero value). + LTE, ///< Signed less than or equal comparison (result is either 0 or + ///< some target-specific non-zero value). + Mod, ///< Signed remainder. Mul, ///< Multiplication. NE, ///< Inequality comparison. Or, ///< Bitwise or. - Shl, ///< Bitwise shift left. - Shr, ///< Bitwise shift right. + Shl, ///< Shift left. + Shr, ///< Shift right (arithmetic or logical, depending on target) Sub, ///< Subtraction. Xor ///< Bitwise exclusive or. }; diff --git a/lib/MC/MCExpr.cpp b/lib/MC/MCExpr.cpp index afdaa00926..e419043a77 100644 --- a/lib/MC/MCExpr.cpp +++ b/lib/MC/MCExpr.cpp @@ -252,8 +252,8 @@ bool MCExpr::EvaluateAsRelocatable(MCValue &Res) const { } // FIXME: We need target hooks for the evaluation. It may be limited in - // width, and gas defines the result of comparisons differently from Apple - // as (the result is sign extended). + // width, and gas defines the result of comparisons and right shifts + // differently from Apple as. int64_t LHS = LHSValue.getConstant(), RHS = RHSValue.getConstant(); int64_t Result = 0; switch (ABE->getOpcode()) { |