[builtin] Fixed definitions of builtins that rely on the int/long long type is 32/64 bits

Summary:
The definition of the builtins __builtin_bswap32, __builtin_bitreverse32, __builtin_rotateleft32 and __builtin_rotateright32 rely on that the int type is 32 bits wide on the target.
The defintions of the builtins __builtin_bswap64, __builtin_bitreverse64, __builtin_rotateleft64, and __builtin_rotateright64 rely on that the long long type is 64 bits wide.

On targets where this is not the case (e.g. AVR) clang will generate faulty code (wrong llvm assembler intrinsics).

This patch add support for using 'Z' (the int32_t type) in Bultins.def. The builtins above are changed to be based on the int32_t type instead of the int type, and the int64_t type instead of the long long type.

The AVR backend (experimental) have a native int type that is only 16 bits wide. The supplied testcase will therefore fail if running the testcase on trunk as clang will convert e.g. __builtin_bitreverse32 into llvm.bitreverse.i16 on AVR.

Reviewers: dylanmckay, spatel, rsmith, efriedma

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D61845

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@360863 91177308-0d34-0410-b5e6-96231b3b80d8

include/clang/Basic/Builtins.def

@@ -50,7 +50,8 @@
 //  L   -> long (e.g. Li for 'long int', Ld for 'long double')
 //  LL  -> long long (e.g. LLi for 'long long int', LLd for __float128)
 //  LLL -> __int128_t (e.g. LLLi)
-//  W   -> int64_t
+//  Z   -> int32_t (require a native 32-bit integer type on the target)
+//  W   -> int64_t (require a native 64-bit integer type on the target)
 //  N   -> 'int' size if target is LP64, 'L' otherwise.
 //  S   -> signed
 //  U   -> unsigned
@@ -418,25 +419,27 @@ BUILTIN(__builtin_clrsb  , "ii"  , "nc")
 BUILTIN(__builtin_clrsbl , "iLi" , "nc")
 BUILTIN(__builtin_clrsbll, "iLLi", "nc")
 
-// FIXME: These type signatures are not correct for targets with int != 32-bits
-// or with ULL != 64-bits.
+// The following builtins rely on that char == 8 bits, short == 16 bits and that
+// there exists native types on the target that are 32- and 64-bits wide, unless
+// these conditions are fulfilled these builtins will operate on a not intended
+// bitwidth.
 BUILTIN(__builtin_bswap16, "UsUs", "nc")
-BUILTIN(__builtin_bswap32, "UiUi", "nc")
-BUILTIN(__builtin_bswap64, "ULLiULLi", "nc")
+BUILTIN(__builtin_bswap32, "UZiUZi", "nc")
+BUILTIN(__builtin_bswap64, "UWiUWi", "nc")
 
 BUILTIN(__builtin_bitreverse8, "UcUc", "nc")
 BUILTIN(__builtin_bitreverse16, "UsUs", "nc")
-BUILTIN(__builtin_bitreverse32, "UiUi", "nc")
-BUILTIN(__builtin_bitreverse64, "ULLiULLi", "nc")
+BUILTIN(__builtin_bitreverse32, "UZiUZi", "nc")
+BUILTIN(__builtin_bitreverse64, "UWiUWi", "nc")
 
 BUILTIN(__builtin_rotateleft8, "UcUcUc", "nc")
 BUILTIN(__builtin_rotateleft16, "UsUsUs", "nc")
-BUILTIN(__builtin_rotateleft32, "UiUiUi", "nc")
-BUILTIN(__builtin_rotateleft64, "ULLiULLiULLi", "nc")
+BUILTIN(__builtin_rotateleft32, "UZiUZiUZi", "nc")
+BUILTIN(__builtin_rotateleft64, "UWiUWiUWi", "nc")
 BUILTIN(__builtin_rotateright8, "UcUcUc", "nc")
 BUILTIN(__builtin_rotateright16, "UsUsUs", "nc")
-BUILTIN(__builtin_rotateright32, "UiUiUi", "nc")
-BUILTIN(__builtin_rotateright64, "ULLiULLiULLi", "nc")
+BUILTIN(__builtin_rotateright32, "UZiUZiUZi", "nc")
+BUILTIN(__builtin_rotateright64, "UWiUWiWi", "nc")
 
 // Random GCC builtins
 BUILTIN(__builtin_constant_p, "i.", "nctu")

lib/AST/ASTContext.cpp

@@ -9286,7 +9286,7 @@ static QualType DecodeTypeFromStr(const char *&Str, const ASTContext &Context,
   // Read the prefixed modifiers first.
   bool Done = false;
   #ifndef NDEBUG
-  bool IsSpecialLong = false;
+  bool IsSpecial = false;
   #endif
   while (!Done) {
     switch (*Str++) {
@@ -9305,26 +9305,26 @@ static QualType DecodeTypeFromStr(const char *&Str, const ASTContext &Context,
       Unsigned = true;
       break;
     case 'L':
-      assert(!IsSpecialLong && "Can't use 'L' with 'W' or 'N' modifiers");
+      assert(!IsSpecial && "Can't use 'L' with 'W', 'N' or 'Z' modifiers");
       assert(HowLong <= 2 && "Can't have LLLL modifier");
       ++HowLong;
       break;
     case 'N':
       // 'N' behaves like 'L' for all non LP64 targets and 'int' otherwise.
-      assert(!IsSpecialLong && "Can't use two 'N' or 'W' modifiers!");
+      assert(!IsSpecial && "Can't use two 'N', 'W' or 'Z' modifiers!");
       assert(HowLong == 0 && "Can't use both 'L' and 'N' modifiers!");
       #ifndef NDEBUG
-      IsSpecialLong = true;
+      IsSpecial = true;
       #endif
       if (Context.getTargetInfo().getLongWidth() == 32)
         ++HowLong;
       break;
     case 'W':
       // This modifier represents int64 type.
-      assert(!IsSpecialLong && "Can't use two 'N' or 'W' modifiers!");
+      assert(!IsSpecial && "Can't use two 'N', 'W' or 'Z'  modifiers!");
       assert(HowLong == 0 && "Can't use both 'L' and 'W' modifiers!");
       #ifndef NDEBUG
-      IsSpecialLong = true;
+      IsSpecial = true;
       #endif
       switch (Context.getTargetInfo().getInt64Type()) {
       default:
@@ -9337,6 +9337,27 @@ static QualType DecodeTypeFromStr(const char *&Str, const ASTContext &Context,
         break;
       }
       break;
+    case 'Z':
+      // This modifier represents int32 type.
+      assert(!IsSpecial && "Can't use two 'N', 'W' or 'Z' modifiers!");
+      assert(HowLong == 0 && "Can't use both 'L' and 'Z' modifiers!");
+      #ifndef NDEBUG
+      IsSpecial = true;
+      #endif
+      switch (Context.getTargetInfo().getIntTypeByWidth(32, true)) {
+      default:
+        llvm_unreachable("Unexpected integer type");
+      case TargetInfo::SignedInt:
+        HowLong = 0;
+        break;
+      case TargetInfo::SignedLong:
+        HowLong = 1;
+        break;
+      case TargetInfo::SignedLongLong:
+        HowLong = 2;
+        break;
+      }
+      break;
     }
   }
 

test/CodeGen/avr-builtins.c

@@ -0,0 +1,102 @@
+// RUN: %clang_cc1 -triple avr-unknown-unknown -emit-llvm -o - %s | FileCheck %s
+
+unsigned char bitrev8(unsigned char data) {
+    return __builtin_bitreverse8(data);
+}
+
+// CHECK: define zeroext i8 @bitrev8
+// CHECK: i8 @llvm.bitreverse.i8(i8
+
+unsigned int bitrev16(unsigned int data) {
+    return __builtin_bitreverse16(data);
+}
+
+// CHECK: define i16 @bitrev16
+// CHECK: i16 @llvm.bitreverse.i16(i16
+
+unsigned long bitrev32(unsigned long data) {
+    return __builtin_bitreverse32(data);
+}
+// CHECK: define i32 @bitrev32
+// CHECK: i32 @llvm.bitreverse.i32(i32
+
+unsigned long long bitrev64(unsigned long long data) {
+    return __builtin_bitreverse64(data);
+}
+
+// CHECK: define i64 @bitrev64
+// CHECK: i64 @llvm.bitreverse.i64(i64
+
+unsigned char rotleft8(unsigned char x, unsigned char y) {
+    return __builtin_rotateleft8(x, y);
+}
+
+// CHECK: define zeroext i8 @rotleft8
+// CHECK: i8 @llvm.fshl.i8(i8
+
+unsigned int rotleft16(unsigned int x, unsigned int y) {
+    return __builtin_rotateleft16(x, y);
+}
+
+// CHECK: define i16 @rotleft16
+// CHECK: i16 @llvm.fshl.i16(i16
+
+unsigned long rotleft32(unsigned long x, unsigned long y) {
+    return __builtin_rotateleft32(x, y);
+}
+// CHECK: define i32 @rotleft32
+// CHECK: i32 @llvm.fshl.i32(i32
+
+unsigned long long rotleft64(unsigned long long x, unsigned long long y) {
+    return __builtin_rotateleft64(x, y);
+}
+
+// CHECK: define i64 @rotleft64
+// CHECK: i64 @llvm.fshl.i64(i64
+
+unsigned char rotright8(unsigned char x, unsigned char y) {
+    return __builtin_rotateright8(x, y);
+}
+
+// CHECK: define zeroext i8 @rotright8
+// CHECK: i8 @llvm.fshr.i8(i8
+
+unsigned int rotright16(unsigned int x, unsigned int y) {
+    return __builtin_rotateright16(x, y);
+}
+
+// CHECK: define i16 @rotright16
+// CHECK: i16 @llvm.fshr.i16(i16
+
+unsigned long rotright32(unsigned long x, unsigned long y) {
+    return __builtin_rotateright32(x, y);
+}
+// CHECK: define i32 @rotright32
+// CHECK: i32 @llvm.fshr.i32(i32
+
+unsigned long long rotright64(unsigned long long x, unsigned long long y) {
+    return __builtin_rotateright64(x, y);
+}
+
+// CHECK: define i64 @rotright64
+// CHECK: i64 @llvm.fshr.i64(i64
+
+unsigned int byteswap16(unsigned int x) {
+    return __builtin_bswap16(x);
+}
+
+// CHECK: define i16 @byteswap16
+// CHECK: i16 @llvm.bswap.i16(i16
+
+unsigned long byteswap32(unsigned long x) {
+    return __builtin_bswap32(x);
+}
+// CHECK: define i32 @byteswap32
+// CHECK: i32 @llvm.bswap.i32(i32
+
+unsigned long long byteswap64(unsigned long long x) {
+    return __builtin_bswap64(x);
+}
+
+// CHECK: define i64 @byteswap64
+// CHECK: i64 @llvm.bswap.i64(i64

test/CodeGen/builtins.cpp

@@ -0,0 +1,52 @@
+// RUN: %clang_cc1 -std=c++11 -triple x86_64-linux-gnu -ffreestanding -verify %s
+// RUN: %clang_cc1 -std=c++11 -triple i686-pc-linux-gnu -ffreestanding -verify %s
+// RUN: %clang_cc1 -std=c++11 -triple avr-unknown-unknown -ffreestanding -verify %s
+
+// expected-no-diagnostics
+
+// Test that checks that the builtins return the same type as the stdint.h type
+// withe the same witdh. This is done by first declaring a variable of a stdint
+// type of the correct width and the redeclaring the variable with the type that
+// the builting return. If the types are different you should the an error from
+// clang of the form:
+// "redefinition of '<varname>' with a different type: '<type1>' vs '<type2>'
+// (with gcc you get an error message
+// "conflicting declaration '<type> <varname>'").
+
+#include <stdint.h>
+
+extern uint16_t bswap16;
+decltype(__builtin_bswap16(0)) bswap16 = 42;
+extern uint32_t bswap32;
+decltype(__builtin_bswap32(0)) bswap32 = 42;
+extern uint64_t bswap64;
+decltype(__builtin_bswap64(0)) bswap64 = 42;
+
+#ifdef __clang__
+extern uint8_t bitrev8;
+decltype(__builtin_bitreverse8(0)) bitrev8 = 42;
+extern uint16_t bitrev16;
+decltype(__builtin_bitreverse16(0)) bitrev16 = 42;
+extern uint32_t bitrev32;
+decltype(__builtin_bitreverse32(0)) bitrev32 = 42;
+extern uint64_t bitrev64;
+decltype(__builtin_bitreverse64(0)) bitrev64 = 42;
+
+extern uint8_t rotl8;
+decltype(__builtin_rotateleft8(0,0)) rotl8 = 42;
+extern uint16_t rotl16;
+decltype(__builtin_rotateleft16(0,0)) rotl16 = 42;
+extern uint32_t rotl32;
+decltype(__builtin_rotateleft32(0,0)) rotl32 = 42;
+extern uint64_t rotl64;
+decltype(__builtin_rotateleft64(0,0)) rotl64 = 42;
+
+extern uint8_t rotr8;
+decltype(__builtin_rotateright8(0,0)) rotr8 = 42;
+extern uint16_t rotr16;
+decltype(__builtin_rotateright16(0,0)) rotr16 = 42;
+extern uint32_t rotr32;
+decltype(__builtin_rotateright32(0,0)) rotr32 = 42;
+extern uint64_t rotr64;
+decltype(__builtin_rotateright64(0,0)) rotr64 = 42;
+#endif