Reduce the size of the ExtInfo bitfield in FunctionType from 9 bits
down to 8 by restricting the maximum allowed regparm value to 6
(previously it was 7). I need the extra bit in Type to handle
instantiation-dependence.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@133924 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/clang/AST/Type.h b/include/clang/AST/Type.h
index 945d17f..e280cb7 100644
--- a/include/clang/AST/Type.h
+++ b/include/clang/AST/Type.h
@@ -1139,7 +1139,7 @@
/// Extra information which affects how the function is called, like
/// regparm and the calling convention.
- unsigned ExtInfo : 9;
+ unsigned ExtInfo : 8;
/// Whether the function is variadic. Only used by FunctionProtoType.
unsigned Variadic : 1;
@@ -2474,18 +2474,19 @@
// * AST read and write
// * Codegen
class ExtInfo {
- // Feel free to rearrange or add bits, but if you go over 9,
+ // Feel free to rearrange or add bits, but if you go over 8,
// you'll need to adjust both the Bits field below and
// Type::FunctionTypeBitfields.
- // | CC |noreturn|produces|hasregparm|regparm
- // |0 .. 2| 3 | 4 | 5 |6 .. 8
+ // | CC |noreturn|produces|regparm|
+ // |0 .. 2| 3 | 4 | 5 .. 7|
+ //
+ // regparm is either 0 (no regparm attribute) or the regparm value+1.
enum { CallConvMask = 0x7 };
enum { NoReturnMask = 0x8 };
enum { ProducesResultMask = 0x10 };
- enum { HasRegParmMask = 0x20 };
enum { RegParmMask = ~(CallConvMask | NoReturnMask | ProducesResultMask),
- RegParmOffset = 6 }; // Assumed to be the last field
+ RegParmOffset = 5 }; // Assumed to be the last field
uint16_t Bits;
@@ -2498,11 +2499,11 @@
// have all the elements (when reading an AST file for example).
ExtInfo(bool noReturn, bool hasRegParm, unsigned regParm, CallingConv cc,
bool producesResult) {
+ assert((!hasRegParm || regParm < 7) && "Invalid regparm value");
Bits = ((unsigned) cc) |
(noReturn ? NoReturnMask : 0) |
(producesResult ? ProducesResultMask : 0) |
- (hasRegParm ? HasRegParmMask : 0) |
- (regParm << RegParmOffset);
+ (hasRegParm ? ((regParm + 1) << RegParmOffset) : 0);
}
// Constructor with all defaults. Use when for example creating a
@@ -2511,8 +2512,13 @@
bool getNoReturn() const { return Bits & NoReturnMask; }
bool getProducesResult() const { return Bits & ProducesResultMask; }
- bool getHasRegParm() const { return Bits & HasRegParmMask; }
- unsigned getRegParm() const { return Bits >> RegParmOffset; }
+ bool getHasRegParm() const { return (Bits >> RegParmOffset) != 0; }
+ unsigned getRegParm() const {
+ unsigned RegParm = Bits >> RegParmOffset;
+ if (RegParm > 0)
+ --RegParm;
+ return RegParm;
+ }
CallingConv getCC() const { return CallingConv(Bits & CallConvMask); }
bool operator==(ExtInfo Other) const {
@@ -2540,9 +2546,9 @@
}
ExtInfo withRegParm(unsigned RegParm) const {
+ assert(RegParm < 7 && "Invalid regparm value");
return ExtInfo((Bits & ~RegParmMask) |
- (HasRegParmMask) |
- (RegParm << RegParmOffset));
+ ((RegParm + 1) << RegParmOffset));
}
ExtInfo withCallingConv(CallingConv cc) const {
diff --git a/include/clang/Basic/TargetInfo.h b/include/clang/Basic/TargetInfo.h
index f0c3d0a..a1625bf 100644
--- a/include/clang/Basic/TargetInfo.h
+++ b/include/clang/Basic/TargetInfo.h
@@ -524,6 +524,7 @@
// getRegParmMax - Returns maximal number of args passed in registers.
unsigned getRegParmMax() const {
+ assert(RegParmMax < 7 && "RegParmMax value is larger than AST can handle");
return RegParmMax;
}