avoid unnecessary shifting

dktapps · dktapps · commit 9074ff40085f · 2023-11-06T18:51:36.000Z
diff --git a/encoding.cpp b/encoding.cpp
@@ -14,6 +14,7 @@ extern "C" {
 #include "ZendUtil.h"
 #include <algorithm>
 #include <iterator>
+#include <type_traits>
 
 ZEND_BEGIN_ARG_WITH_RETURN_TYPE_INFO_EX(arginfo_read_integer, 0, 0, IS_LONG, 0)
 ZEND_END_ARG_INFO()
@@ -137,7 +138,7 @@ static inline bool readInt24(unsigned char* bytes, size_t used, size_t& offset,
 		result |= bytes[offset] << 16;
 	}
 
-	const size_t SIGNED_SHIFT = (sizeof(TValue) - SIZE) * CHAR_BIT;
+	const size_t SIGNED_SHIFT = std::is_signed<TValue>::value ? (sizeof(TValue) - SIZE) * CHAR_BIT : 0;
 	if (SIGNED_SHIFT > 0) {
 		result = (result << SIGNED_SHIFT) >> SIGNED_SHIFT;
 	}

Original file line number	Diff line number	Diff line change
`@@ -14,6 +14,7 @@ extern "C" {`
`14`	`14`	`#include "ZendUtil.h"`
`15`	`15`	`#include <algorithm>`
`16`	`16`	`#include <iterator>`
	`17`	`+#include <type_traits>`
`17`	`18`
`18`	`19`	`ZEND_BEGIN_ARG_WITH_RETURN_TYPE_INFO_EX(arginfo_read_integer, 0, 0, IS_LONG, 0)`
`19`	`20`	`ZEND_END_ARG_INFO()`
`@@ -137,7 +138,7 @@ static inline bool readInt24(unsigned char* bytes, size_t used, size_t& offset,`
`137`	`138`	`result \|= bytes[offset] << 16;`
`138`	`139`	`}`
`139`	`140`
`140`		`- const size_t SIGNED_SHIFT = (sizeof(TValue) - SIZE) * CHAR_BIT;`
	`141`	`+ const size_t SIGNED_SHIFT = std::is_signed<TValue>::value ? (sizeof(TValue) - SIZE) * CHAR_BIT : 0;`
`141`	`142`	`if (SIGNED_SHIFT > 0) {`
`142`	`143`	`result = (result << SIGNED_SHIFT) >> SIGNED_SHIFT;`
`143`	`144`	`}`