Question

我试图在PPC64-LE上编译源文件。我正在使用xlC编译器，编译失败。 GCC接受该计划，所以我不确定问题的原因是什么。

这是命令行：

$ xlc test-p8.c -qarch=pwr8 -qaltivec -o test-p8.exe

这是编译错误：

"test-p8.c", line 113.52: 1506-324 (S) "int" cannot be converted to "vector unsigned int".
"test-p8.c", line 120.15: 1506-068 (S) Operation between types "vector unsigned int" and "int" is not allowed.
"test-p8.c", line 121.15: 1506-068 (S) Operation between types "vector unsigned int" and "int" is not allowed.
"test-p8.c", line 122.15: 1506-068 (S) Operation between types "vector unsigned int" and "int" is not allowed.
"test-p8.c", line 123.15: 1506-068 (S) Operation between types "vector unsigned int" and "int" is not allowed.
"test-p8.c", line 124.15: 1506-068 (S) Operation between types "vector unsigned int" and "int" is not allowed.
"test-p8.c", line 125.15: 1506-068 (S) Operation between types "vector unsigned int" and "int" is not allowed.
"test-p8.c", line 126.15: 1506-068 (S) Operation between types "vector unsigned int" and "int" is not allowed.
"test-p8.c", line 127.15: 1506-068 (S) Operation between types "vector unsigned int" and "int" is not allowed.
"test-p8.c", line 128.15: 1506-068 (S) Operation between types "vector unsigned int" and "int" is not allowed.
"test-p8.c", line 130.15: 1506-068 (S) Operation between types "vector unsigned int" and "int" is not allowed.

这是源文件的相关部分。源文件是another problem的简化大小写，它是available on GitHub。

$ cat -n test-p8.c
   ...
    12  typedef unsigned char uint8_t;
    13  typedef unsigned long long uint64_t;
    14  typedef vector unsigned char uint8x16_p8;
    15  typedef vector unsigned int uint64x2_p8;
   ...
    76  __attribute__((aligned(16)))
    77  uint8_t ks[176] = {
    78      0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6, 0xab, 0xf7, 0x15, 0x88, 0x9,  0xcf, 0x4f, 0x3c,
   ...
    89  };
   ...
   113  uint64x2_p8 block = (uint64x2_p8)vec_vsx_ld(0U, (const uint8_t*)plain);
   ...
   118  block = vec_xor(block, (uint64x2_p8)vec_ld(0U, (const uint8_t*)ks));
   ...
   120  block = __builtin_crypto_vcipher(block, (uint64x2_p8)vec_ld( 16U, (const uint8_t*)ks));
   121  block = __builtin_crypto_vcipher(block, (uint64x2_p8)vec_ld( 32U, (const uint8_t*)ks));
   122  block = __builtin_crypto_vcipher(block, (uint64x2_p8)vec_ld( 48U, (const uint8_t*)ks));
   123  block = __builtin_crypto_vcipher(block, (uint64x2_p8)vec_ld( 64U, (const uint8_t*)ks));
   124  block = __builtin_crypto_vcipher(block, (uint64x2_p8)vec_ld( 80U, (const uint8_t*)ks));
   125  block = __builtin_crypto_vcipher(block, (uint64x2_p8)vec_ld( 96U, (const uint8_t*)ks));
   126  block = __builtin_crypto_vcipher(block, (uint64x2_p8)vec_ld(112U, (const uint8_t*)ks));
   127  block = __builtin_crypto_vcipher(block, (uint64x2_p8)vec_ld(128U, (const uint8_t*)ks));
   128  block = __builtin_crypto_vcipher(block, (uint64x2_p8)vec_ld(144U, (const uint8_t*)ks));
   129
   130  block = __builtin_crypto_vcipherlast(block, (uint64x2_p8)vec_ld(160U, (const uint8_t*)ks));

__builtin_crypto_vcipher是内置的GCC，IBM声明xlC supports it。

第118行与上面显示的所有其他行类似，但它不会触发警告或错误。

问题是什么，我该如何解决？

Answer 1

在PPC64-LE上，我们花了很多精力来统一GCC和XL之间的矢量内置接口。两个团队共同努力为ABI文档添加一致的界面。你可以在这里找到它：

HTML，PDF

ABI的新vcipher函数是vec_cipher_be，xlC支持。

请注意，新功能的部分原因是某些旧GCC加密函数接受的类型会产生字节序问题。

Answer 2

redbook you linked to是关于IBM Power Systems处理器的性能优化和调优技术，包括IBM POWER8＆＃34;并且不是特定于编译器的。它包含有关POWER8上编译器支持的信息，包括XLC和GCC编译器。

在红皮书的第7.3.1页第149页（如果您使用PDF页面推进器，第171页），请说明以下支持：

GCC ：vector unsigned long long __builtin_crypto_vcipher (vector unsigned long long, vector unsigned long long)
XL C / C ++ ：vector unsigned char __vcipher (vector unsigned char, vector unsigned char)

如果您正在使用GCC进行编译，则应使用__builtin_crypto_vcipher，如果您正在使用XLC进行编译，则应使用__vcipher。

Answer 3

Operation between types "vector unsigned int" and "int" is not allowed

我想我跟踪了这一点。 xlC不知道函数__builtin_crypto_vcipher，因此编译器假定函数接受int作为参数或返回int（我不知道函数是哪一个）时刻）。我相信等效的GCC消息是关于遗漏声明并假设int返回。

稍后，未知函数采用向量而不是int：

__builtin_crypto_vcipher(block, ...)

或者，它为向量指定int：

block = __builtin_crypto_vcipher(...)

当我切换到xlC内置__vcipher时，问题就消失了。

我不知道为什么文档声明xlC接受GCC内置的。

xlC和类型之间的操作＆＃34; vector unsigned int＆＃34;和＆＃34; int＆＃34;不允许

3 个答案: