Merging r328885:

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r328885 | timshen | 2018-03-30 10:51:03 -0700 (Fri, 30 Mar 2018) | 14 lines

[NVPTX] Enable StructuredCFG for NVPTX

Summary:
Make NVPTX require structured CFG. Added a temporary flag to
"roll back" the behavior for easy deployment.

Combined with D45008, this fixes several internal Nvidia GPU test
failures that we suspect to be ptxas miscompiles (PR27738).

Reviewers: jlebar

Subscribers: jholewinski, sanjoy, llvm-commits, hiraditya

Differential Revision: https://reviews.llvm.org/D45070
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_60@333475 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/NVPTX/NVPTXTargetMachine.cpp b/lib/Target/NVPTX/NVPTXTargetMachine.cpp
index d31e1cb5047b7cef7154b5f71a1a8fcaff5addc1..cb8cc7bb347afdc2dba9d1b3f5bb4611acbf2c41 100644 (file)
--- a/lib/Target/NVPTX/NVPTXTargetMachine.cpp
+++ b/lib/Target/NVPTX/NVPTXTargetMachine.cpp
@@ -44,6 +44,14 @@ static cl::opt<bool>
                                cl::desc("Disable load/store vectorizer"),
                                cl::init(false), cl::Hidden);
 
+// TODO: Remove this flag when we are confident with no regressions.
+static cl::opt<bool> DisableRequireStructuredCFG(
+    "disable-nvptx-require-structured-cfg",
+    cl::desc("Transitional flag to turn off NVPTX's requirement on preserving "
+             "structured CFG. The requirement should be disabled only when "
+             "unexpected regressions happen."),
+    cl::init(false), cl::Hidden);
+
 namespace llvm {
 
 void initializeNVVMIntrRangePass(PassRegistry&);
@@ -108,6 +116,8 @@ NVPTXTargetMachine::NVPTXTargetMachine(const Target &T, const Triple &TT,
     drvInterface = NVPTX::NVCL;
   else
     drvInterface = NVPTX::CUDA;
+  if (!DisableRequireStructuredCFG)
+    setRequiresStructuredCFG(true);
   initAsmInfo();
 }