[clang][CodeGen][AMDGPU] Enable AMDGPU printf for spirv64-amd-amdhsa (#97132)

This enables the AMDGPU specific implementation of `printf` when
compiling for AMDGCN flavoured SPIR-V, the consequence being that the
expansion into ROCDL calls & friends gets expanded before "lowering" to
SPIR-V and gets carried through. The only relatively "novel" aspect is
that the `callAppendStringN` is simplified to take the type of the
passed in arguments, as opposed to querying them from the module. This
is a neutral change since the arguments were passed directly to the
call, without any attempt to cast them, hence the assumption that the
actual types match the formal ones was already baked in.

Author: AlexVlx

clang/lib/CodeGen/CGBuiltin.cpp

@@ -5888,12 +5888,16 @@ RValue CodeGenFunction::EmitBuiltinExpr(const GlobalDecl GD, unsigned BuiltinID,
   case Builtin::BI__builtin_printf:
   case Builtin::BIprintf:
     if (getTarget().getTriple().isNVPTX() ||
-        getTarget().getTriple().isAMDGCN()) {
+        getTarget().getTriple().isAMDGCN() ||
+        (getTarget().getTriple().isSPIRV() &&
+         getTarget().getTriple().getVendor() == Triple::VendorType::AMD)) {
       if (getLangOpts().OpenMPIsTargetDevice)
         return EmitOpenMPDevicePrintfCallExpr(E);
       if (getTarget().getTriple().isNVPTX())
         return EmitNVPTXDevicePrintfCallExpr(E);
-      if (getTarget().getTriple().isAMDGCN() && getLangOpts().HIP)
+      if ((getTarget().getTriple().isAMDGCN() ||
+           getTarget().getTriple().isSPIRV()) &&
+          getLangOpts().HIP)
         return EmitAMDGPUDevicePrintfCallExpr(E);
     }
 

clang/lib/CodeGen/CGGPUBuiltin.cpp

@@ -179,7 +179,9 @@ RValue CodeGenFunction::EmitNVPTXDevicePrintfCallExpr(const CallExpr *E) {
 }
 
 RValue CodeGenFunction::EmitAMDGPUDevicePrintfCallExpr(const CallExpr *E) {
-  assert(getTarget().getTriple().getArch() == llvm::Triple::amdgcn);
+  assert(getTarget().getTriple().isAMDGCN() ||
+         (getTarget().getTriple().isSPIRV() &&
+          getTarget().getTriple().getVendor() == llvm::Triple::AMD));
   assert(E->getBuiltinCallee() == Builtin::BIprintf ||
          E->getBuiltinCallee() == Builtin::BI__builtin_printf);
   assert(E->getNumArgs() >= 1); // printf always has at least one arg.

clang/test/CodeGenHIP/printf-builtin.hip

@@ -1,8 +1,12 @@
 // REQUIRES: amdgpu-registered-target
 // RUN: %clang_cc1 -triple amdgcn-amd-amdhsa -emit-llvm -disable-llvm-optzns -mprintf-kind=hostcall -fno-builtin-printf -fcuda-is-device \
 // RUN:   -o - %s | FileCheck --check-prefixes=CHECK,HOSTCALL %s
+// RUN: %clang_cc1 -triple spirv64-amd-amdhsa -emit-llvm -disable-llvm-optzns -mprintf-kind=hostcall -fno-builtin-printf -fcuda-is-device \
+// RUN:   -o - %s | FileCheck --check-prefixes=CHECK-AMDGCNSPIRV,HOSTCALL-AMDGCNSPIRV %s
 // RUN: %clang_cc1 -triple amdgcn-amd-amdhsa -emit-llvm -disable-llvm-optzns -mprintf-kind=buffered -fno-builtin-printf -fcuda-is-device \
 // RUN:   -o - %s | FileCheck --check-prefixes=CHECK,BUFFERED %s
+// RUN: %clang_cc1 -triple spirv64-amd-amdhsa -emit-llvm -disable-llvm-optzns -mprintf-kind=buffered -fno-builtin-printf -fcuda-is-device \
+// RUN:   -o - %s | FileCheck --check-prefixes=CHECK-AMDGCNSPIRV,BUFFERED-AMDGCNSPIRV %s
 
 #define __device__ __attribute__((device))
 
@@ -11,13 +15,17 @@ extern "C" __device__ int printf(const char *format, ...);
 // CHECK-LABEL: @_Z4foo1v()
 __device__ int foo1() {
   // HOSTCALL: call i64 @__ockl_printf_begin
+  // HOSTCALL-AMDGCNSPIRV: call addrspace(4) i64 @__ockl_printf_begin
   // BUFFERED: call ptr addrspace(1) @__printf_alloc
+  // BUFFERED-AMDGCNSPIRV: call addrspace(4) ptr addrspace(1) @__printf_alloc
   // CHECK-NOT: call i32 (ptr, ...) @printf
+  // CHECK-AMDGCNSPIRV-NOT: call i32 (ptr, ...) @printf
   return __builtin_printf("Hello World\n");
 }
 
 // CHECK-LABEL: @_Z4foo2v()
 __device__ int foo2() {
   // CHECK: call i32 (ptr, ...) @printf
+  // CHECK-AMDGCNSPIRV: call spir_func addrspace(4) i32 (ptr addrspace(4), ...) @printf
   return printf("Hello World\n");
 }