[AMDGPU] More verifier checks for llvm.amdgcn.cs.chain

[rovka]

Summary

Check that the SGPR arguments have the inreg attribute and the VGPR
arguments don't.

[rovka]

Rebase.

llvm/lib/IR/Verifier.cpp

case CallingConv::AMDGPU_CS_ChainPreserve:
       break;
     default:
       CheckFailed("Intrinsic can only be used from functions with the "
                   "amdgpu_cs, amdgpu_cs_chain or amdgpu_cs_chain_preserve "
                   "calling conventions",
                   &Call);
       break;
     }
+
+    Check(Call.paramHasAttr(2, Attribute::InReg),
+          "SGPR arguments must have the `inreg` attribute", &Call);
+    Check(!Call.paramHasAttr(3, Attribute::InReg),
+          "VGPR arguments must not have the `inreg` attribute", &Call);
     break;
   }
   case Intrinsic::experimental_convergence_entry:
     Check(Call.getFunction()->isConvergent(),
           "Entry intrinsic can occur only in a convergent function.", &Call);
     Check(Call.getParent()->isEntryBlock(),
           "Entry intrinsic must occur in the entry block.", &Call);
     Check(Call.getParent()->getFirstNonPHI() == &Call,

llvm/test/Verifier/AMDGPU/intrinsic-amdgpu-cs-chain.ll

 ; RUN: not llvm-as %s -o /dev/null 2>&1 | FileCheck %s
 
 declare void @llvm.amdgcn.cs.chain(ptr, i32, <4 x i32>, { ptr, <3 x i32> }, i32, ...) noreturn
 
 define amdgpu_cs_chain void @bad_flags(ptr %fn, i32 %exec, <4 x i32> inreg %sgpr, { ptr, <3 x i32> } %vgpr, i32 %flags) {
   ; CHECK: immarg operand has non-immediate parameter
   ; CHECK-NEXT: i32 %flags
   ; CHECK-NEXT: @llvm.amdgcn.cs.chain
   call void(ptr, i32, <4 x i32>, { ptr, <3 x i32> }, i32, ...) @llvm.amdgcn.cs.chain(ptr %fn, i32 %exec, <4 x i32> %sgpr, { ptr, <3 x i32> } %vgpr, i32 %flags)
   unreachable
 }
 
+define amdgpu_cs_chain void @bad_vgpr_args(ptr %fn, i32 %exec, <4 x i32> inreg %sgpr, { ptr, <3 x i32> } inreg %vgpr) {
+  ; CHECK: VGPR arguments must not have the `inreg` attribute
+  ; CHECK-NEXT: @llvm.amdgcn.cs.chain
+  call void(ptr, i32, <4 x i32>, { ptr, <3 x i32> }, i32, ...) @llvm.amdgcn.cs.chain(ptr %fn, i32 %exec, <4 x i32> inreg %sgpr, { ptr, <3 x i32> } inreg %vgpr, i32 0)
+  unreachable
+}
+
+define amdgpu_cs_chain void @bad_sgpr_args(ptr %fn, i32 %exec, <4 x i32> %sgpr, { ptr, <3 x i32> } %vgpr) {
+  ; CHECK: SGPR arguments must have the `inreg` attribute
+  ; CHECK-NEXT: @llvm.amdgcn.cs.chain
+  call void(ptr, i32, <4 x i32>, { ptr, <3 x i32> }, i32, ...) @llvm.amdgcn.cs.chain(ptr %fn, i32 %exec, <4 x i32> %sgpr, { ptr, <3 x i32> } %vgpr, i32 0)
+  unreachable
+}
+
 define amdgpu_cs_chain void @bad_exec(ptr %fn, i32 %exec, <4 x i32> inreg %sgpr, { ptr, <3 x i32> } %vgpr, i32 %flags) {
   ; CHECK: Intrinsic called with incompatible signature
   ; CHECK-NEXT: @llvm.amdgcn.cs.chain
   call void(ptr, <4 x i32>, <4 x i32>, { ptr, <3 x i32> }, i32, ...) @llvm.amdgcn.cs.chain(ptr %fn, <4 x i32> %sgpr, <4 x i32> %sgpr, { ptr, <3 x i32> } %vgpr, i32 %flags)
   unreachable
 }
 
 define void @bad_caller_default_cc(ptr %fn, i32 %exec, <4 x i32> inreg %sgpr, { ptr, <3 x i32> } %vgpr) {