[PATCH] D19990: [CUDA] Implement __ldg using intrinsics.

[Justin Lebar via cfe-commits]

jlebar added inline comments.

================
Comment at: include/clang/Basic/BuiltinsNVPTX.def:569-603
@@ -568,1 +568,37 @@
 
+// __ldg.  This is not implemented as a builtin by nvcc.
+BUILTIN(__nvvm_ldg_c, "ccC*", "")
+BUILTIN(__nvvm_ldg_s, "ssC*", "")
+BUILTIN(__nvvm_ldg_i, "iiC*", "")
+BUILTIN(__nvvm_ldg_l, "LiLiC*", "")
+BUILTIN(__nvvm_ldg_ll, "LLiLLiC*", "")
+
+BUILTIN(__nvvm_ldg_uc, "UcUcC*", "")
+BUILTIN(__nvvm_ldg_us, "UsUsC*", "")
+BUILTIN(__nvvm_ldg_ui, "UiUiC*", "")
+BUILTIN(__nvvm_ldg_ul, "ULiULiC*", "")
+BUILTIN(__nvvm_ldg_ull, "ULLiULLiC*", "")
+
+BUILTIN(__nvvm_ldg_f, "ffC*", "")
+BUILTIN(__nvvm_ldg_d, "ddC*", "")
+
+BUILTIN(__nvvm_ldg_c2, "E2cE2cC*", "")
+BUILTIN(__nvvm_ldg_c4, "E4cE4cC*", "")
+BUILTIN(__nvvm_ldg_s2, "E2sE2sC*", "")
+BUILTIN(__nvvm_ldg_s4, "E4sE4sC*", "")
+BUILTIN(__nvvm_ldg_i2, "E2iE2iC*", "")
+BUILTIN(__nvvm_ldg_i4, "E4iE4iC*", "")
+BUILTIN(__nvvm_ldg_ll2, "E2LLiE2LLiC*", "")
+
+BUILTIN(__nvvm_ldg_uc2, "E2UcE2UcC*", "")
+BUILTIN(__nvvm_ldg_uc4, "E4UcE4UcC*", "")
+BUILTIN(__nvvm_ldg_us2, "E2UsE2UsC*", "")
+BUILTIN(__nvvm_ldg_us4, "E4UsE4UsC*", "")
+BUILTIN(__nvvm_ldg_ui2, "E2UiE2UiC*", "")
+BUILTIN(__nvvm_ldg_ui4, "E4UiE4UiC*", "")
+BUILTIN(__nvvm_ldg_ull2, "E2ULLiE2ULLiC*", "")
+
+BUILTIN(__nvvm_ldg_f2, "E2fE2fC*", "")
+BUILTIN(__nvvm_ldg_f4, "E4fE4fC*", "")
+BUILTIN(__nvvm_ldg_d2, "E2dE2dC*", "")
+
----------------
majnemer wrote:
> Would it be crazy to instead provide a generic builtin? Would cut down on the number of variants...
> 
> `__builtin_add_overflow` is an example of such a builtin.
Art is going to send you flowers.  :)  He and I just had an argument about this.

I think this isn't an unreasonable thing to want, but I think it's beneficial to be consistent with our existing API.  So if we offer a generic thing for ldg, it would be nice to have one for atomics above, which are basically the same.

So I told Art I'd prefer to add it to our list.


http://reviews.llvm.org/D19990