[llvm] AMDGPU/GlobalISel: Handle inreg arguments as SGPRs (PR #78123)

[Jun Wang via llvm-commits]

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@@ -2777,4 +2777,462 @@ define void @vector_ptr_in_struct_arg({ <2 x ptr addrspace(1)>, <2 x ptr addrspa
   ret void
 }
 
+define void @void_func_i1_inreg(i1 inreg %arg0) #0 {
+  ; CHECK-LABEL: name: void_func_i1_inreg
+  ; CHECK: bb.1 (%ir-block.0):
+  ; CHECK-NEXT:   liveins: $sgpr0
+  ; CHECK-NEXT: {{  $}}
+  ; CHECK-NEXT:   [[COPY:%[0-9]+]]:_(s32) = COPY $sgpr0
+  ; CHECK-NEXT:   [[TRUNC:%[0-9]+]]:_(s1) = G_TRUNC [[COPY]](s32)
+  ; CHECK-NEXT:   [[DEF:%[0-9]+]]:_(p1) = G_IMPLICIT_DEF
+  ; CHECK-NEXT:   G_STORE [[TRUNC]](s1), [[DEF]](p1) :: (store (s1) into `ptr addrspace(1) undef`, addrspace 1)
+  ; CHECK-NEXT:   SI_RETURN
+  store i1 %arg0, ptr addrspace(1) undef
+  ret void
+}
+
+define void @void_func_i8_inreg(i8 inreg %arg0) #0 {
+  ; CHECK-LABEL: name: void_func_i8_inreg
+  ; CHECK: bb.1 (%ir-block.0):
+  ; CHECK-NEXT:   liveins: $sgpr0
+  ; CHECK-NEXT: {{  $}}
+  ; CHECK-NEXT:   [[COPY:%[0-9]+]]:_(s32) = COPY $sgpr0
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jwanggit86 wrote:

For some GPUs, isn't it true that sgpr0-spgr3 are reserved?

https://github.com/llvm/llvm-project/pull/78123