[Fixed Point Arithmetic] Fixed Point Precision Bits and Fixed Point Literals
This diff includes the logic for setting the precision bits for each primary fixed point type in the target info and logic for initializing a fixed point literal.
Fixed point literals are declared using the suffixes
```
hr: short _Fract
uhr: unsigned short _Fract
r: _Fract
ur: unsigned _Fract
lr: long _Fract
ulr: unsigned long _Fract
hk: short _Accum
uhk: unsigned short _Accum
k: _Accum
uk: unsigned _Accum
```
Errors are also thrown for illegal literal values
```
unsigned short _Accum u_short_accum = 256.0uhk; // expected-error{{the integral part of this literal is too large for this unsigned _Accum type}}
```
Differential Revision: https://reviews.llvm.org/D46915
llvm-svn: 335148
diff --git a/clang/test/Frontend/fixed_point.c b/clang/test/Frontend/fixed_point.c
index bc8cf2d..3a67718 100644
--- a/clang/test/Frontend/fixed_point.c
+++ b/clang/test/Frontend/fixed_point.c
@@ -236,4 +236,164 @@
//CHECK-NEXT: |-VarDecl {{.*}} SatlA_type 'SatlA_t':'_Sat long _Accum'
//CHECK-NEXT: |-VarDecl {{.*}} SatsF_type 'SatsF_t':'_Sat short _Fract'
//CHECK-NEXT: |-VarDecl {{.*}} SatF_type 'SatF_t':'_Sat _Fract'
-//CHECK-NEXT: `-VarDecl {{.*}} SatlF_type 'SatlF_t':'_Sat long _Fract'
+//CHECK-NEXT: |-VarDecl {{.*}} SatlF_type 'SatlF_t':'_Sat long _Fract'
+
+// Fixed point literal exponent syntax
+_Accum decexp1 = 1.575e1k;
+_Accum decexp2 = 1.575E1k;
+_Accum decexp3 = 1575e-2k;
+_Accum decexp4 = 1575E-2k;
+
+_Accum hexexp1 = 0x0.3p10k;
+_Accum hexexp2 = 0x0.3P10k;
+_Accum hexexp3 = 0x30000p-10k;
+_Accum hexexp4 = 0x30000P-10k;
+
+_Accum zeroexp1 = 1e0k;
+_Accum zeroexp2 = 1e-0k;
+
+//CHECK-NEXT: |-VarDecl {{.*}} decexp1 '_Accum' cinit
+//CHECK-NEXT: `-FixedPointLiteral {{.*}} '_Accum' 15.75
+//CHECK-NEXT: |-VarDecl {{.*}} decexp2 '_Accum' cinit
+//CHECK-NEXT: `-FixedPointLiteral {{.*}} '_Accum' 15.75
+//CHECK-NEXT: |-VarDecl {{.*}} decexp3 '_Accum' cinit
+//CHECK-NEXT: `-FixedPointLiteral {{.*}} '_Accum' 15.75
+//CHECK-NEXT: |-VarDecl {{.*}} decexp4 '_Accum' cinit
+//CHECK-NEXT: `-FixedPointLiteral {{.*}} '_Accum' 15.75
+
+//CHECK-NEXT: |-VarDecl {{.*}} hexexp1 '_Accum' cinit
+//CHECK-NEXT: `-FixedPointLiteral {{.*}} '_Accum' 192.0
+//CHECK-NEXT: |-VarDecl {{.*}} hexexp2 '_Accum' cinit
+//CHECK-NEXT: `-FixedPointLiteral {{.*}} '_Accum' 192.0
+//CHECK-NEXT: |-VarDecl {{.*}} hexexp3 '_Accum' cinit
+//CHECK-NEXT: `-FixedPointLiteral {{.*}} '_Accum' 192.0
+//CHECK-NEXT: |-VarDecl {{.*}} hexexp4 '_Accum' cinit
+//CHECK-NEXT: `-FixedPointLiteral {{.*}} '_Accum' 192.0
+
+//CHECK-NEXT: |-VarDecl {{.*}} zeroexp1 '_Accum' cinit
+//CHECK-NEXT: `-FixedPointLiteral {{.*}} '_Accum' 1.0
+//CHECK-NEXT: |-VarDecl {{.*}} zeroexp2 '_Accum' cinit
+//CHECK-NEXT: `-FixedPointLiteral {{.*}} '_Accum' 1.0
+
+// Fixed point literal values
+_Accum literal1 = 2.5k; // Precise decimal
+_Accum literal2 = 0.0k; // Zero
+_Accum literal3 = 1.1k; // Imprecise decimal
+_Accum literal4 = 1.11k;
+_Accum literal5 = 1.111k;
+_Accum literal6 = 1.1111k;
+_Accum literal7 = 1.11111k; // After some point after the radix, adding any more
+ // digits to the literal will not result in any
+ // further precision since the nth digit added may
+ // be less than the precision that can be
+ // represented by the fractional bits of the type.
+ // This results in the same value being stored for
+ // the type.
+
+//CHECK-NEXT: |-VarDecl {{.*}} literal1 '_Accum' cinit
+//CHECK-NEXT: `-FixedPointLiteral {{.*}} '_Accum' 2.5
+//CHECK-NEXT: |-VarDecl {{.*}} literal2 '_Accum' cinit
+//CHECK-NEXT: `-FixedPointLiteral {{.*}} '_Accum' 0.0
+//CHECK-NEXT: |-VarDecl {{.*}} literal3 '_Accum' cinit
+//CHECK-NEXT: `-FixedPointLiteral {{.*}} '_Accum' 1.0999755859375
+//CHECK-NEXT: |-VarDecl {{.*}} literal4 '_Accum' cinit
+//CHECK-NEXT: `-FixedPointLiteral {{.*}} '_Accum' 1.1099853515625
+//CHECK-NEXT: |-VarDecl {{.*}} literal5 '_Accum' cinit
+//CHECK-NEXT: `-FixedPointLiteral {{.*}} '_Accum' 1.110992431640625
+//CHECK-NEXT: |-VarDecl {{.*}} literal6 '_Accum' cinit
+//CHECK-NEXT: `-FixedPointLiteral {{.*}} '_Accum' 1.111083984375
+//CHECK-NEXT: |-VarDecl {{.*}} literal7 '_Accum' cinit
+//CHECK-NEXT: `-FixedPointLiteral {{.*}} '_Accum' 1.111083984375
+
+long _Accum longaccumliteral = 0.99999999lk;
+long _Accum longaccumliteral2 = 0.999999999lk;
+long _Accum verylongaccumliteral = 0.99999999999999999999999999lk;
+long _Fract longfractliteral = 0.99999999lr;
+long _Fract longfractliteral2 = 0.999999999lr;
+long _Fract verylongfractliteral = 0.99999999999999999999999999lr;
+
+//CHECK-NEXT: |-VarDecl {{.*}} longaccumliteral 'long _Accum' cinit
+//CHECK-NEXT: `-FixedPointLiteral {{.*}} 'long _Accum' 0.999999989755451679229736328125
+//CHECK-NEXT: |-VarDecl {{.*}} longaccumliteral2 'long _Accum' cinit
+//CHECK-NEXT: `-FixedPointLiteral {{.*}} 'long _Accum' 0.9999999986030161380767822265625
+//CHECK-NEXT: |-VarDecl {{.*}} verylongaccumliteral 'long _Accum' cinit
+//CHECK-NEXT: `-FixedPointLiteral {{.*}} 'long _Accum' 0.9999999995343387126922607421875
+//CHECK-NEXT: |-VarDecl {{.*}} longfractliteral 'long _Fract' cinit
+//CHECK-NEXT: `-FixedPointLiteral {{.*}} 'long _Fract' 0.999999989755451679229736328125
+//CHECK-NEXT: |-VarDecl {{.*}} longfractliteral2 'long _Fract' cinit
+//CHECK-NEXT: `-FixedPointLiteral {{.*}} 'long _Fract' 0.9999999986030161380767822265625
+//CHECK-NEXT: |-VarDecl {{.*}} verylongfractliteral 'long _Fract' cinit
+//CHECK-NEXT: `-FixedPointLiteral {{.*}} 'long _Fract' 0.9999999995343387126922607421875
+
+unsigned _Accum uliteral1 = 2.5uk; // Unsigned
+_Accum literal8 = -2.5k; // Negative
+
+//CHECK-NEXT: |-VarDecl {{.*}} uliteral1 'unsigned _Accum' cinit
+//CHECK-NEXT: `-FixedPointLiteral {{.*}} 'unsigned _Accum' 2.5
+//CHECK-NEXT: |-VarDecl {{.*}} literal8 '_Accum' cinit
+//CHECK-NEXT: `-UnaryOperator {{.*}} '_Accum' prefix '-'
+//CHECK-NEXT: `-FixedPointLiteral {{.*}} '_Accum' 2.5
+
+short _Accum literalexact1 = 0.9921875hk; // Exact value
+_Accum literalexact2 = 0.999969482421875k;
+
+//CHECK-NEXT: |-VarDecl {{.*}} literalexact1 'short _Accum' cinit
+//CHECK-NEXT: `-FixedPointLiteral {{.*}} 'short _Accum' 0.9921875
+//CHECK-NEXT: |-VarDecl {{.*}} literalexact2 '_Accum' cinit
+//CHECK-NEXT: `-FixedPointLiteral {{.*}} '_Accum' 0.999969482421875
+
+// Unfortunately we do not have enough space to store the exact decimal value of
+// 0.9999999995343387126922607421875 ((1 << 31) - 1), but we can still use a
+// large number of 9s to get the max fractional value.
+long _Accum long_accum_max = 0.999999999999999999999999999lk;
+
+//CHECK-NEXT: |-VarDecl {{.*}} long_accum_max 'long _Accum' cinit
+//CHECK-NEXT: `-FixedPointLiteral {{.*}} 'long _Accum' 0.9999999995343387126922607421875
+
+// Epsilon
+short _Accum short_accum_eps = 0.0078125hk;
+short _Accum short_accum_eps2 = 0.0078124hk; // Less than epsilon floors to zero
+_Accum accum_eps = 0.000030517578125k;
+_Accum accum_eps2 = 0.000030517578124k;
+long _Accum long_accum_eps = 0x1p-31lk;
+long _Accum long_accum_eps2 = 0x0.99999999p-31lk;
+
+//CHECK-NEXT: |-VarDecl {{.*}} short_accum_eps 'short _Accum' cinit
+//CHECK-NEXT: `-FixedPointLiteral {{.*}} 'short _Accum' 0.0078125
+//CHECK-NEXT: |-VarDecl {{.*}} short_accum_eps2 'short _Accum' cinit
+//CHECK-NEXT: `-FixedPointLiteral {{.*}} 'short _Accum' 0.0
+//CHECK-NEXT: |-VarDecl {{.*}} accum_eps '_Accum' cinit
+//CHECK-NEXT: `-FixedPointLiteral {{.*}} '_Accum' 0.000030517578125
+//CHECK-NEXT: |-VarDecl {{.*}} accum_eps2 '_Accum' cinit
+//CHECK-NEXT: `-FixedPointLiteral {{.*}} '_Accum' 0.0
+//CHECK-NEXT: |-VarDecl {{.*}} long_accum_eps 'long _Accum' cinit
+//CHECK-NEXT: `-FixedPointLiteral {{.*}} 'long _Accum' 0.0000000004656612873077392578125
+//CHECK-NEXT: |-VarDecl {{.*}} long_accum_eps2 'long _Accum' cinit
+//CHECK-NEXT: `-FixedPointLiteral {{.*}} 'long _Accum' 0.0
+
+// Fract literals can be one but evaluate to the respective Fract max
+short _Fract short_fract_one = 1.0hr;
+_Fract fract_one = 1.0r;
+long _Fract long_fract_one = 1.0lr;
+unsigned short _Fract u_short_fract_one = 1.0uhr;
+unsigned _Fract u_fract_one = 1.0ur;
+unsigned long _Fract u_long_fract_one = 1.0ulr;
+
+//CHECK-NEXT: |-VarDecl {{.*}} short_fract_one 'short _Fract' cinit
+//CHECK-NEXT: `-FixedPointLiteral {{.*}} 'short _Fract' 0.9921875
+//CHECK-NEXT: |-VarDecl {{.*}} fract_one '_Fract' cinit
+//CHECK-NEXT: `-FixedPointLiteral {{.*}} '_Fract' 0.999969482421875
+//CHECK-NEXT: |-VarDecl {{.*}} long_fract_one 'long _Fract' cinit
+//CHECK-NEXT: `-FixedPointLiteral {{.*}} 'long _Fract' 0.9999999995343387126922607421875
+
+//CHECK-NEXT: |-VarDecl {{.*}} u_short_fract_one 'unsigned short _Fract' cinit
+//CHECK-NEXT: `-FixedPointLiteral {{.*}} 'unsigned short _Fract' 0.99609375
+//CHECK-NEXT: |-VarDecl {{.*}} u_fract_one 'unsigned _Fract' cinit
+//CHECK-NEXT: `-FixedPointLiteral {{.*}} 'unsigned _Fract' 0.9999847412109375
+//CHECK-NEXT: |-VarDecl {{.*}} u_long_fract_one 'unsigned long _Fract' cinit
+//CHECK-NEXT: `-FixedPointLiteral {{.*}} 'unsigned long _Fract' 0.99999999976716935634613037109375
+
+_Accum literallast = 1.0k; // One
+
+//CHECK-NEXT: `-VarDecl {{.*}} literallast '_Accum' cinit
+//CHECK-NEXT: `-FixedPointLiteral {{.*}} '_Accum' 1.0