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Improved simplifyMathFunctions when simplifying special cases of pow(x,y)-function.

This commit is contained in:
Martin Ettl 2013-09-29 15:11:09 +02:00
parent ee9b7283ec
commit 0527aefb11
5 changed files with 91 additions and 3 deletions
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5
lib/mathlib.cpp
View File

@ -121,6 +121,11 @@ bool MathLib::isNegative(const std::string &s)
return (s[n] == '-');
}
bool MathLib::isPositive(const std::string &s)
{
return !MathLib::isNegative(s);
}
bool MathLib::isOct(const std::string& str)
{
bool sign = str[0]=='-' || str[0]=='+';

1
lib/mathlib.h
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@ -45,6 +45,7 @@ public:
static bool isInt(const std::string & str);
static bool isFloat(const std::string &str);
static bool isNegative(const std::string &str);
static bool isPositive(const std::string &str);
static bool isHex(const std::string& str);
static bool isOct(const std::string& str);
static bool isBin(const std::string& str);

61
lib/tokenize.cpp
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@ -8377,10 +8377,9 @@ void Tokenizer::simplifyMathFunctions()
tok->deleteNext(5); // delete tokens
tok->str((isLessOrGreater == true) ? "true": "false"); // insert results
}
} else if (Token::Match(tok, "div|ldiv|lldiv|pow|powf|powl ( %any% , %num% )")) {
} else if (Token::Match(tok, "div|ldiv|lldiv ( %any% , %num% )")) {
// Calling the function 'div(x,y)' is the same as calculating (x)/(y). In case y has the value 1
// (the identity element), the call can be simplified to (x).
// In case of pow( anyNumber,1 ): It can be simplified to anynumber.
const std::string leftParameter(tok->tokAt(2)->str()); // get the left parameter
const std::string rightNumber(tok->tokAt(4)->str()); // get right number
if (!rightNumber.empty() && !leftParameter.empty()) {
@ -8388,12 +8387,68 @@ void Tokenizer::simplifyMathFunctions()
const bool isInteger = MathLib::isInt(rightNumber);
const bool isFloat = MathLib::isFloat(rightNumber);
const bool allowToSimplify = ((!isNegative && isInteger && (MathLib::toLongNumber(rightNumber) == 1L)) // case: integer numbers
|| (!isNegative && isFloat && (MathLib::toDoubleNumber(rightNumber)-1.0) <= 0.)); // case: float numbers
|| (!isNegative && isFloat && (MathLib::toDoubleNumber(rightNumber)-1.0) >= 0.)); // case: float numbers
if (allowToSimplify == true) {
tok->deleteNext(5); // delete tokens
tok->str(leftParameter); // insert simplified result
}
}
} else if (Token::Match(tok, "pow|powf|powl (")) {
if (tok && Token::Match(tok->tokAt(2), " %any% , %num% )")) {
// In case of pow( x , 1 ): It can be simplified to x.
const std::string leftParameter(tok->tokAt(2)->str()); // get the left parameter
const std::string rightNumber(tok->tokAt(4)->str()); // get right number
if (!rightNumber.empty() && !leftParameter.empty()) {
const bool isNegative = MathLib::isNegative(rightNumber);
const bool isInteger = MathLib::isInt(rightNumber);
const bool isFloat = MathLib::isFloat(rightNumber);
const bool rightParameterIsOne = ((!isNegative && isInteger && (MathLib::toLongNumber(rightNumber) == 1L)) // case: integer numbers
|| (!isNegative && isFloat && (MathLib::toDoubleNumber(rightNumber)-1.0) >= 0.)); // case: float numbers
const bool rightParameterIsZero = ((!isNegative && isInteger && (MathLib::toLongNumber(rightNumber) == 0L)) // case: integer numbers
|| (!isNegative && isFloat && (MathLib::toDoubleNumber(rightNumber)) >= 0.)); // case: float numbers
if (rightParameterIsOne) { // case: x^(1) = x
tok->deleteNext(5); // delete tokens
tok->str(leftParameter); // insert simplified result
} else if (rightParameterIsZero) { // case: x^(0) = 1
tok->deleteNext(5); // delete tokens
tok->str("1"); // insert simplified result
}
}
}
if (tok && Token::Match(tok->tokAt(2), " %num% , %num% )")) {
// In case of pow ( 0 , anyNumber > 0): It can be simplified to 0
// In case of pow ( 0 , 0 ): It simplified to 1
// In case of pow ( 1 , anyNumber ): It simplified to 1
const std::string leftNumber(tok->tokAt(2)->str()); // get the left parameter
const std::string rightNumber(tok->tokAt(4)->str()); // get the right parameter
if (!leftNumber.empty()) {
const bool isLeftNumberNegative = MathLib::isNegative(leftNumber);
const bool isLeftNumberInteger = MathLib::isInt(leftNumber);
const bool isLeftNumberFloat = MathLib::isFloat(leftNumber);
const bool isRightNumberNegative = MathLib::isNegative(rightNumber);
const bool isRightNumberInteger = MathLib::isInt(rightNumber);
const bool isRightNumberFloat = MathLib::isFloat(rightNumber);
const bool isLeftNumberZero = ((!isLeftNumberNegative && isLeftNumberInteger && (MathLib::toLongNumber(leftNumber) == 0L)) // case: integer numbers
|| (!isLeftNumberNegative && isLeftNumberFloat && (MathLib::toDoubleNumber(leftNumber)) >= 0.)); // case: float numbers
const bool isLeftNumberOne = ((isLeftNumberNegative && isLeftNumberInteger && (MathLib::toLongNumber(leftNumber) == 1L)) // case: integer numbers
|| (!isLeftNumberNegative && isLeftNumberFloat && (MathLib::toDoubleNumber(leftNumber)) >= 1.)); // case: float numbers
const bool isRightNumberZero = ((!isRightNumberNegative && isRightNumberInteger && (MathLib::toLongNumber(rightNumber) == 0L)) // case: integer numbers
|| (!isRightNumberNegative && isRightNumberFloat && (MathLib::toDoubleNumber(rightNumber)) >= 0.)); // case: float numbers
if (isLeftNumberZero && !isRightNumberZero && MathLib::isPositive(rightNumber)) { // case: 0^(y) = 0 and y > 0
tok->deleteNext(5); // delete tokens
tok->str("0"); // insert simplified result
}
if (isLeftNumberZero && isRightNumberZero) { // case: 0^0 = 1
tok->deleteNext(5); // delete tokens
tok->str("1"); // insert simplified result
}
if (isLeftNumberOne) { // case 1^(y) = 1
tok->deleteNext(5); // delete tokens
tok->str("1"); // insert simplified result
}
}
}
}
}
}

15
test/testmathlib.cpp
View File

@ -34,6 +34,7 @@ private:
TEST_CASE(convert);
TEST_CASE(isint);
TEST_CASE(isnegative);
TEST_CASE(ispositive);
TEST_CASE(isfloat);
TEST_CASE(isGreater)
TEST_CASE(isGreaterEqual)
@ -312,6 +313,20 @@ private:
ASSERT_EQUALS(false, MathLib::isNegative("+1.0E-2"));
}
void ispositive() const {
ASSERT_EQUALS(false, MathLib::isPositive("-1"));
ASSERT_EQUALS(false, MathLib::isPositive("-1."));
ASSERT_EQUALS(false, MathLib::isPositive("-1.0"));
ASSERT_EQUALS(false, MathLib::isPositive("-1.0E+2"));
ASSERT_EQUALS(false, MathLib::isPositive("-1.0E-2"));
ASSERT_EQUALS(true , MathLib::isPositive("+1"));
ASSERT_EQUALS(true , MathLib::isPositive("+1."));
ASSERT_EQUALS(true , MathLib::isPositive("+1.0"));
ASSERT_EQUALS(true , MathLib::isPositive("+1.0E+2"));
ASSERT_EQUALS(true , MathLib::isPositive("+1.0E-2"));
}
void isfloat() const {
ASSERT_EQUALS(false, MathLib::isFloat("0"));
ASSERT_EQUALS(true , MathLib::isFloat("0."));

12
test/testtokenize.cpp
View File

@ -8346,6 +8346,18 @@ private:
const char expected_pow1[] = "int f ( const Fred & fred ) { return fred . pow ( 12 , 3 ) ; }";
ASSERT_EQUALS(expected_pow1, tokenizeAndStringify(code_pow1));
const char code_pow2[] = "int f() {return pow(0,0);}";
const char expected_pow2[] = "int f ( ) { return 1 ; }";
ASSERT_EQUALS(expected_pow2, tokenizeAndStringify(code_pow2));
const char code_pow3[] = "int f() {return pow(0,1);}";
const char expected_pow3[] = "int f ( ) { return 0 ; }";
ASSERT_EQUALS(expected_pow3, tokenizeAndStringify(code_pow3));
const char code_pow4[] = "int f() {return pow(1,0);}";
const char expected_pow4[] = "int f ( ) { return 1 ; }";
ASSERT_EQUALS(expected_pow4, tokenizeAndStringify(code_pow4));
// verify islessgreater() simplification
const char code_islessgreater[] = "bool f(){\n"
"return islessgreater(1,0);\n" // (1 < 0) or (1 > 0) --> true