[clang] [HIP] fix host min/max in header (PR #82956)

[Yaxun Liu via cfe-commits]

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@@ -1306,15 +1306,73 @@ float min(float __x, float __y) { return __builtin_fminf(__x, __y); }
 __DEVICE__
 double min(double __x, double __y) { return __builtin_fmin(__x, __y); }
 
-#if !defined(__HIPCC_RTC__) && !defined(__OPENMP_AMDGCN__)
-__host__ inline static int min(int __arg1, int __arg2) {
-  return __arg1 < __arg2 ? __arg1 : __arg2;
+// Define host min/max functions.
+#if !defined(__HIPCC_RTC__) && !defined(__OPENMP_AMDGCN__) &&                  \
+    !defined(__HIP_NO_HOST_MIN_MAX_IN_GLOBAL_NAMESPACE__)
+
+#pragma push_macro("DEFINE_MIN_MAX_FUNCTIONS")
+#pragma push_macro("DEFINE_MIN_MAX_FUNCTIONS")
+#define DEFINE_MIN_MAX_FUNCTIONS(ret_type, type1, type2)                       \
+  inline ret_type min(const type1 __a, const type2 __b) {                      \
+    return (__a < __b) ? __a : __b;                                            \
+  }                                                                            \
+  inline ret_type max(const type1 __a, const type2 __b) {                      \
+    return (__a > __b) ? __a : __b;                                            \
+  }
+
+// Define min and max functions for same type comparisons
+DEFINE_MIN_MAX_FUNCTIONS(int, int, int)
+DEFINE_MIN_MAX_FUNCTIONS(unsigned int, unsigned int, unsigned int)
+DEFINE_MIN_MAX_FUNCTIONS(long, long, long)
+DEFINE_MIN_MAX_FUNCTIONS(unsigned long, unsigned long, unsigned long)
+DEFINE_MIN_MAX_FUNCTIONS(long long, long long, long long)
+DEFINE_MIN_MAX_FUNCTIONS(unsigned long long, unsigned long long,
+                         unsigned long long)
+
+// CUDA defines host min/max functions with mixed signed/unsgined integer
+// parameters where signed integers are casted to unsigned integers. However,
+// this may not be users' intention. Therefore do not define them by default
+// unless users specify -D__HIP_DEFINE_MIXED_HOST_MIN_MAX__.
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yxsamliu wrote:

I reverted this PR due to regression in hipCUB:

https://github.com/ROCm/hipCUB/blob/develop/hipcub/include/hipcub/backend/rocprim/device/device_spmv.hpp#L142

hipCUB/hipcub/include/hipcub/backend/rocprim/device/device_spmv.hpp:142:33: error: call to 'min' is ambiguous

it is a call of min(int, unsigned int). The code is likely ported from CUDA.

Probably I need to define those functions with mixed args by default to avoid regressions.

https://github.com/llvm/llvm-project/pull/82956