Drop QEMU_GNUC_PREREQ() checks for gcc older than 4.1

We already require gcc 4.1 or newer (for the atomic
support), so the fallback codepaths for older gcc
versions than that are now dead code and we can
just delete them.

NB: clang reports itself as gcc 4.2 (regardless of
clang version), so clang won't be using the fallbacks
either.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>

include/qemu/compiler.h

@@ -24,17 +24,9 @@
 
 #define QEMU_NORETURN __attribute__ ((__noreturn__))
 
-#if QEMU_GNUC_PREREQ(3, 4)
 #define QEMU_WARN_UNUSED_RESULT __attribute__((warn_unused_result))
-#else
-#define QEMU_WARN_UNUSED_RESULT
-#endif
 
-#if QEMU_GNUC_PREREQ(4, 0)
 #define QEMU_SENTINEL __attribute__((sentinel))
-#else
-#define QEMU_SENTINEL
-#endif
 
 #if QEMU_GNUC_PREREQ(4, 3)
 #define QEMU_ARTIFICIAL __attribute__((always_inline, artificial))

include/qemu/host-utils.h

@@ -115,37 +115,7 @@ static inline uint64_t muldiv64(uint64_t a, uint32_t b, uint32_t c)
  */
 static inline int clz32(uint32_t val)
 {
-#if QEMU_GNUC_PREREQ(3, 4)
     return val ? __builtin_clz(val) : 32;
-#else
-    /* Binary search for the leading one bit.  */
-    int cnt = 0;
-
-    if (!(val & 0xFFFF0000U)) {
-        cnt += 16;
-        val <<= 16;
-    }
-    if (!(val & 0xFF000000U)) {
-        cnt += 8;
-        val <<= 8;
-    }
-    if (!(val & 0xF0000000U)) {
-        cnt += 4;
-        val <<= 4;
-    }
-    if (!(val & 0xC0000000U)) {
-        cnt += 2;
-        val <<= 2;
-    }
-    if (!(val & 0x80000000U)) {
-        cnt++;
-        val <<= 1;
-    }
-    if (!(val & 0x80000000U)) {
-        cnt++;
-    }
-    return cnt;
-#endif
 }
 
 /**
@@ -168,19 +138,7 @@ static inline int clo32(uint32_t val)
  */
 static inline int clz64(uint64_t val)
 {
-#if QEMU_GNUC_PREREQ(3, 4)
     return val ? __builtin_clzll(val) : 64;
-#else
-    int cnt = 0;
-
-    if (!(val >> 32)) {
-        cnt += 32;
-    } else {
-        val >>= 32;
-    }
-
-    return cnt + clz32(val);
-#endif
 }
 
 /**
@@ -203,39 +161,7 @@ static inline int clo64(uint64_t val)
  */
 static inline int ctz32(uint32_t val)
 {
-#if QEMU_GNUC_PREREQ(3, 4)
     return val ? __builtin_ctz(val) : 32;
-#else
-    /* Binary search for the trailing one bit.  */
-    int cnt;
-
-    cnt = 0;
-    if (!(val & 0x0000FFFFUL)) {
-        cnt += 16;
-        val >>= 16;
-    }
-    if (!(val & 0x000000FFUL)) {
-        cnt += 8;
-        val >>= 8;
-    }
-    if (!(val & 0x0000000FUL)) {
-        cnt += 4;
-        val >>= 4;
-    }
-    if (!(val & 0x00000003UL)) {
-        cnt += 2;
-        val >>= 2;
-    }
-    if (!(val & 0x00000001UL)) {
-        cnt++;
-        val >>= 1;
-    }
-    if (!(val & 0x00000001UL)) {
-        cnt++;
-    }
-
-    return cnt;
-#endif
 }
 
 /**
@@ -258,19 +184,7 @@ static inline int cto32(uint32_t val)
  */
 static inline int ctz64(uint64_t val)
 {
-#if QEMU_GNUC_PREREQ(3, 4)
     return val ? __builtin_ctzll(val) : 64;
-#else
-    int cnt;
-
-    cnt = 0;
-    if (!((uint32_t)val)) {
-        cnt += 32;
-        val >>= 32;
-    }
-
-    return cnt + ctz32(val);
-#endif
 }
 
 /**
@@ -322,15 +236,7 @@ static inline int clrsb64(uint64_t val)
  */
 static inline int ctpop8(uint8_t val)
 {
-#if QEMU_GNUC_PREREQ(3, 4)
     return __builtin_popcount(val);
-#else
-    val = (val & 0x55) + ((val >> 1) & 0x55);
-    val = (val & 0x33) + ((val >> 2) & 0x33);
-    val = (val + (val >> 4)) & 0x0f;
-
-    return val;
-#endif
 }
 
 /**
@@ -339,16 +245,7 @@ static inline int ctpop8(uint8_t val)
  */
 static inline int ctpop16(uint16_t val)
 {
-#if QEMU_GNUC_PREREQ(3, 4)
     return __builtin_popcount(val);
-#else
-    val = (val & 0x5555) + ((val >> 1) & 0x5555);
-    val = (val & 0x3333) + ((val >> 2) & 0x3333);
-    val = (val + (val >> 4)) & 0x0f0f;
-    val = (val + (val >> 8)) & 0x00ff;
-
-    return val;
-#endif
 }
 
 /**
@@ -357,16 +254,7 @@ static inline int ctpop16(uint16_t val)
  */
 static inline int ctpop32(uint32_t val)
 {
-#if QEMU_GNUC_PREREQ(3, 4)
     return __builtin_popcount(val);
-#else
-    val = (val & 0x55555555) + ((val >> 1) & 0x55555555);
-    val = (val & 0x33333333) + ((val >> 2) & 0x33333333);
-    val = (val + (val >> 4)) & 0x0f0f0f0f;
-    val = (val * 0x01010101) >> 24;
-
-    return val;
-#endif
 }
 
 /**
@@ -375,16 +263,7 @@ static inline int ctpop32(uint32_t val)
  */
 static inline int ctpop64(uint64_t val)
 {
-#if QEMU_GNUC_PREREQ(3, 4)
     return __builtin_popcountll(val);
-#else
-    val = (val & 0x5555555555555555ULL) + ((val >> 1) & 0x5555555555555555ULL);
-    val = (val & 0x3333333333333333ULL) + ((val >> 2) & 0x3333333333333333ULL);
-    val = (val + (val >> 4)) & 0x0f0f0f0f0f0f0f0fULL;
-    val = (val * 0x0101010101010101ULL) >> 56;
-
-    return val;
-#endif
 }
 
 /**

tcg/arm/tcg-target.h

@@ -130,14 +130,7 @@ enum {
 
 static inline void flush_icache_range(uintptr_t start, uintptr_t stop)
 {
-#if QEMU_GNUC_PREREQ(4, 1)
     __builtin___clear_cache((char *) start, (char *) stop);
-#else
-    register uintptr_t _beg __asm("a1") = start;
-    register uintptr_t _end __asm("a2") = stop;
-    register uintptr_t _flg __asm("a3") = 0;
-    __asm __volatile__ ("swi 0x9f0002" : : "r" (_beg), "r" (_end), "r" (_flg));
-#endif
 }
 
 #endif