portable rotate (idiom recognised & optimised by gcc/clang)

Author: moon-chilled

jsrc/j.h

@@ -2258,6 +2258,9 @@ extern I CTLZI_(UI,UI4*);
 #define BLSR(x) ((x)&~BLSI(x))
 #endif
 
+static inline UI4 rol32(UI4 x,I s){ R (x<<s)|(x>>(32-x)); }
+static inline UI4 ror32(UI4 x,I s){ R (x>>s)|(x<<(32-x)); }
+
 // Set these switches for testing
 #define AUDITBP 0  // Verify that bp() returns expected data
 #define AUDITCOMPILER 0  // Verify compiler features CTTZ, signed >>

jsrc/viavx.c

@@ -177,7 +177,7 @@ static I hashallo(IH * RESTRICT hh,UI p,UI asct,I md){
 // CRC32L takes UIL (8 bytes)
 
 // obsolete #define RETCRC3 R CRC32L(crc0,CRC32L(crc1,crc2))
-#define RETCRC3 R CRC32L(crc0,(UI)__builtin_rotateleft32(crc1,9)+((UI)__builtin_rotateleft32(crc2,21)<<32))
+#define RETCRC3 R CRC32L(crc0,(UI)rol32(crc1,9)+((UI)rol32(crc2,21)<<32))
 // Create CRC32 of the k bytes in *v.  Uses CRC32L to process 8 bytes at a time
 // We may fetch past the end of the input, but only up to the next SZI-byte block
 UI hic(I k, UC *v) {