Enable .ptr .global .align attributes for kernel attributes for CUDA (llvm#114874)

Emit .ptr, .address-space, and .align attributes for kernel
args in CUDA (previously handled only for OpenCL).

This allows for more vectorization opportunities if the PTX consumer
is able to know about the pointer alignments.

If no alignment is explicitly specified, .align 1 will be emitted
to match the LLVM IR semantics in this case.

PTX ISA doc -
https://docs.nvidia.com/cuda/parallel-thread-execution/index.html#kernel-parameter-attribute-ptr

This is a rework of the original patch proposed in llvm#79646

---------

Co-authored-by: Vandana <[email protected]>

Author: LewisCrawford

llvm/lib/Target/NVPTX/NVPTXAsmPrinter.cpp

@@ -1600,30 +1600,27 @@ void NVPTXAsmPrinter::emitFunctionParamList(const Function *F, raw_ostream &O) {
 
       if (isKernelFunc) {
         if (PTy) {
-          // Special handling for pointer arguments to kernel
-          O << "\t.param .u" << PTySizeInBits << " ";
-
-          if (static_cast<NVPTXTargetMachine &>(TM).getDrvInterface() !=
-              NVPTX::CUDA) {
-            int addrSpace = PTy->getAddressSpace();
-            switch (addrSpace) {
-            default:
-              O << ".ptr ";
-              break;
-            case ADDRESS_SPACE_CONST:
-              O << ".ptr .const ";
-              break;
-            case ADDRESS_SPACE_SHARED:
-              O << ".ptr .shared ";
-              break;
-            case ADDRESS_SPACE_GLOBAL:
-              O << ".ptr .global ";
-              break;
-            }
-            Align ParamAlign = I->getParamAlign().valueOrOne();
-            O << ".align " << ParamAlign.value() << " ";
+          O << "\t.param .u" << PTySizeInBits << " .ptr";
+
+          switch (PTy->getAddressSpace()) {
+          default:
+            break;
+          case ADDRESS_SPACE_GLOBAL:
+            O << " .global";
+            break;
+          case ADDRESS_SPACE_SHARED:
+            O << " .shared";
+            break;
+          case ADDRESS_SPACE_CONST:
+            O << " .const";
+            break;
+          case ADDRESS_SPACE_LOCAL:
+            O << " .local";
+            break;
           }
-          O << TLI->getParamName(F, paramIndex);
+
+          O << " .align " << I->getParamAlign().valueOrOne().value();
+          O << " " << TLI->getParamName(F, paramIndex);
           continue;
         }
 

llvm/test/CodeGen/NVPTX/i1-param.ll

@@ -8,7 +8,7 @@ target triple = "nvptx-nvidia-cuda"
 
 ; CHECK: .entry foo
 ; CHECK:   .param .u8 foo_param_0
-; CHECK:   .param .u64 foo_param_1
+; CHECK:   .param .u64 .ptr .align 1 foo_param_1
 define void @foo(i1 %p, ptr %out) {
   %val = zext i1 %p to i32
   store i32 %val, ptr %out

llvm/test/CodeGen/NVPTX/kernel-param-align.ll

@@ -0,0 +1,42 @@
+; RUN: llc < %s -march=nvptx64 -mcpu=sm_60 | FileCheck %s
+; RUN: %if ptxas %{ llc < %s -march=nvptx64 -mcpu=sm_60 | %ptxas-verify %}
+
+%struct.Large = type { [16 x double] }
+
+; CHECK-LABEL: .entry func_align(
+; CHECK: .param .u64 .ptr         .align 1  func_align_param_0
+; CHECK: .param .u64 .ptr         .align 2  func_align_param_1
+; CHECK: .param .u64 .ptr .global .align 4  func_align_param_2
+; CHECK: .param .u64 .ptr .shared .align 8  func_align_param_3
+; CHECK: .param .u64 .ptr .const  .align 16 func_align_param_4
+; CHECK: .param .u64 .ptr .local  .align 32 func_align_param_5
+define void @func_align(ptr nocapture readonly align 1 %input,
+                        ptr nocapture align 2 %out,
+                        ptr addrspace(1) align 4 %global,
+                        ptr addrspace(3) align 8 %shared,
+                        ptr addrspace(4) align 16 %const,
+                        ptr addrspace(5) align 32 %local) {
+entry:
+  ret void
+}
+
+; CHECK-LABEL: .entry func_noalign(
+; CHECK: .param .u64 .ptr         .align 1 func_noalign_param_0
+; CHECK: .param .u64 .ptr         .align 1 func_noalign_param_1
+; CHECK: .param .u64 .ptr .global .align 1 func_noalign_param_2
+; CHECK: .param .u64 .ptr .shared .align 1 func_noalign_param_3
+; CHECK: .param .u64 .ptr .const  .align 1 func_noalign_param_4
+; CHECK: .param .u64 .ptr .local  .align 1 func_noalign_param_5
+define void @func_noalign(ptr nocapture readonly %input,
+                          ptr nocapture %out,
+                          ptr addrspace(1) %global,
+                          ptr addrspace(3) %shared,
+                          ptr addrspace(4) %const,
+                          ptr addrspace(5) %local) {
+entry:
+  ret void
+}
+
+!nvvm.annotations = !{!0, !1}
+!0 = !{ptr @func_align, !"kernel", i32 1}
+!1 = !{ptr @func_noalign, !"kernel", i32 1}