[NVPTX] Allow undef value as global initializer

Summary:
__shared__ variable may now emit undef value as initializer, do not
throw error on that.

Test Plan: test/CodeGen/NVPTX/global-addrspace.ll

Patch by Xuetian Weng

Reviewers: jholewinski, tra, jingyue

Subscribers: llvm-commits, jholewinski

Differential Revision: http://reviews.llvm.org/D12242

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@245785 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/NVPTX/NVPTXAsmPrinter.cpp b/lib/Target/NVPTX/NVPTXAsmPrinter.cpp
index ffdac61f44d5cb2d229d1abf9c5a0c6d06ba56c4..16afe3cbfb51ab55606947416810056c93f2eea4 100644 (file)
--- a/lib/Target/NVPTX/NVPTXAsmPrinter.cpp
+++ b/lib/Target/NVPTX/NVPTXAsmPrinter.cpp
@@ -1183,9 +1183,11 @@ void NVPTXAsmPrinter::printModuleLevelGV(const GlobalVariable *GVar,
           printScalarConstant(Initializer, O);
         }
       } else {
-        // The frontend adds zero-initializer to variables that don't have an
-        // initial value, so skip warning for this case.
-        if (!GVar->getInitializer()->isNullValue()) {
+        // The frontend adds zero-initializer to device and constant variables
+        // that don't have an initial value, and UndefValue to shared
+        // variables, so skip warning for this case.
+        if (!GVar->getInitializer()->isNullValue() &&
+            !isa<UndefValue>(GVar->getInitializer())) {
           report_fatal_error("initial value of '" + GVar->getName() +
                              "' is not allowed in addrspace(" +
                              Twine(PTy->getAddressSpace()) + ")");

diff --git a/test/CodeGen/NVPTX/global-addrspace.ll b/test/CodeGen/NVPTX/global-addrspace.ll
new file mode 100644 (file)
index 0000000..4da14c7
--- /dev/null
+++ b/test/CodeGen/NVPTX/global-addrspace.ll
@@ -0,0 +1,12 @@
+; RUN: llc < %s -march=nvptx -mcpu=sm_20 | FileCheck %s --check-prefix=PTX32
+; RUN: llc < %s -march=nvptx64 -mcpu=sm_20 | FileCheck %s --check-prefix=PTX64
+
+; PTX32: .visible .global .align 4 .u32 i;
+; PTX32: .visible .const .align 4 .u32 j;
+; PTX32: .visible .shared .align 4 .u32 k;
+; PTX64: .visible .global .align 4 .u32 i;
+; PTX64: .visible .const .align 4 .u32 j;
+; PTX64: .visible .shared .align 4 .u32 k;
+@i = addrspace(1) externally_initialized global i32 0, align 4
+@j = addrspace(4) externally_initialized global i32 0, align 4
+@k = addrspace(3) global i32 undef, align 4