Fix builtin vars translation (#1738)

The translator was crashing in case if builin GV was accessed via
GEP without AS cast due to incorrect assumption.

Signed-off-by: Sidorov, Dmitry <[email protected]>

Author: MrSidims

lib/SPIRV/SPIRVUtil.cpp

@@ -2021,6 +2021,12 @@ bool lowerBuiltinVariableToCall(GlobalVariable *GV,
           llvm_unreachable("Unexpected pattern!");
         }
       }
+    } else if (auto *GEP = dyn_cast<GetElementPtrInst>(UI)) {
+      GEPs.push_back(GEP);
+      for (auto *GEPUser : GEP->users()) {
+        if (!ReplaceIfLoad(GEPUser))
+          llvm_unreachable("Unexpected pattern!");
+      }
     } else if (!ReplaceIfLoad(UI)) {
       llvm_unreachable("Unexpected pattern!");
     }

test/transcoding/builtin_vars_gep.ll

@@ -0,0 +1,42 @@
+; RUN: llvm-as %s -o %t.bc
+; RUN: llvm-spirv %t.bc -o %t.spv
+; RUN: llvm-spirv %t.spv -to-text -o - | FileCheck %s --check-prefix=CHECK-SPIRV
+; RUN: spirv-val %t.spv
+; RUN: llvm-spirv -r -emit-opaque-pointers %t.spv -o %t.out.bc
+; RUN: llvm-dis %t.out.bc -o - | FileCheck %s --check-prefix=CHECK-OCL-IR
+; RUN: llvm-spirv -r -emit-opaque-pointers %t.spv --spirv-target-env=SPV-IR -o %t.out.bc
+; RUN: llvm-dis %t.out.bc -o - | FileCheck %s --check-prefix=CHECK-SPV-IR
+
+; Check that produced builtin-call-based SPV-IR is recognized by the translator
+; RUN: llvm-spirv -spirv-text %t.out.bc -o - | FileCheck %s --check-prefix=CHECK-SPIRV
+
+; CHECK-SPIRV: Decorate [[Id:[0-9]+]] BuiltIn 28
+; CHECK-SPIRV: Variable {{[0-9]+}} [[Id:[0-9]+]]
+
+target datalayout = "e-p:32:32-i64:64-v16:16-v24:32-v32:32-v48:64-v96:128-v192:256-v256:256-v512:512-v1024:1024"
+target triple = "spir-unknown-unknown"
+
+@__spirv_BuiltInGlobalInvocationId = external dso_local local_unnamed_addr addrspace(1) constant <3 x i64>, align 32
+
+; Function Attrs: nounwind readnone
+define spir_kernel void @f() {
+entry:
+  %0 = load i64, i64 addrspace(1)* getelementptr (<3 x i64>, <3 x i64> addrspace(1)* @__spirv_BuiltInGlobalInvocationId, i64 0, i64 0), align 32
+  ; CHECK-OCL-IR: %[[#ID1:]] = call spir_func i64 @_Z13get_global_idj(i32 0)
+  ; CHECK-OCL-IR: %[[#VEC1:]] = insertelement <3 x i64> undef, i64 %[[#ID1]], i32 0
+  ; CHECK-OCL-IR: %[[#ID2:]] = call spir_func i64 @_Z13get_global_idj(i32 1)
+  ; CHECK-OCL-IR: %[[#VEC2:]] = insertelement <3 x i64> %[[#VEC1]], i64 %[[#ID2]], i32 1
+  ; CHECK-OCL-IR: %[[#ID3:]] = call spir_func i64 @_Z13get_global_idj(i32 2)
+  ; CHECK-OCL-IR: %[[#VEC3:]] = insertelement <3 x i64> %[[#VEC2]], i64 %[[#ID3]], i32 2
+  ; CHECK-OCL-IR: %[[#]] = extractelement <3 x i64> %[[#VEC3]], i64 0
+
+  ; CHECK-SPV-IR: %[[#ID1:]] = call spir_func i64 @_Z33__spirv_BuiltInGlobalInvocationIdi(i32 0)
+  ; CHECK-SPV-IR: %[[#VEC1:]] = insertelement <3 x i64> undef, i64 %[[#ID1]], i32 0
+  ; CHECK-SPV-IR: %[[#ID2:]] = call spir_func i64 @_Z33__spirv_BuiltInGlobalInvocationIdi(i32 1)
+  ; CHECK-SPV-IR: %[[#VEC2:]] = insertelement <3 x i64> %[[#VEC1]], i64 %[[#ID2]], i32 1
+  ; CHECK-SPV-IR: %[[#ID3:]] = call spir_func i64 @_Z33__spirv_BuiltInGlobalInvocationIdi(i32 2)
+  ; CHECK-SPV-IR: %[[#VEC3:]] = insertelement <3 x i64> %[[#VEC2]], i64 %[[#ID3]], i32 2
+  ; CHECK-SPV-IR: %[[#]] = extractelement <3 x i64> %[[#VEC3]], i64 0
+
+  ret void
+}