[clang] [AMDGPU] Treat printf as builtin for OpenCL (PR #72554)

[Vikram Hegde via cfe-commits]

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@@ -406,5 +410,9 @@ TARGET_BUILTIN(__builtin_amdgcn_cvt_pk_fp8_f32, "iffiIb", "nc", "fp8-insts")
 TARGET_BUILTIN(__builtin_amdgcn_cvt_sr_bf8_f32, "ifiiIi", "nc", "fp8-insts")
 TARGET_BUILTIN(__builtin_amdgcn_cvt_sr_fp8_f32, "ifiiIi", "nc", "fp8-insts")
 
+// OpenCL
+LANGBUILTIN(printf, "icC*4.", "fp:0:", ALL_OCL_LANGUAGES)
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vikramRH wrote:

@ssahasra , I still feel this is the way to move here since I dont see a way to access the printf option at IR level and thus decide version of printf to use. It has to be at clang CodeGen. I ask other reviewers too if they feel there are major concerns with adding such a builtin variant (i.e AMDGPU and OCL specific). I might have to look for alternative approaches if so. 

https://github.com/llvm/llvm-project/pull/72554