[PATCH] D73721: [Clang][Driver] Disable llvm passes for the first host OpenMP offload compilation

[Sergey Dmitriev via Phabricator via cfe-commits]

sdmitriev created this revision.
sdmitriev added reviewers: ABataev, jdoerfert, hfinkel.
Herald added subscribers: cfe-commits, guansong.
Herald added a project: clang.

With OpenMP offloading host compilation is done in two phases to capture host IR that is passed to all device compilations as input. But it turns out that we currently run entire LLVM optimization pipeline on host IR on both compilations which may have unpredictable effects on the resulting code. This patch fixes this problem by disabling LLVM passes on the first compilation, so the host IR that is passed to device compilations will be captured right after front end.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D73721

Files:
  clang/lib/Driver/ToolChains/Clang.cpp
  clang/test/Driver/openmp-offload.c


Index: clang/test/Driver/openmp-offload.c
===================================================================
--- clang/test/Driver/openmp-offload.c
+++ clang/test/Driver/openmp-offload.c
@@ -259,7 +259,7 @@
 //
 // Generate host BC file and host object.
 //
-// CHK-COMMANDS: clang{{.*}}" "-cc1" "-triple" "powerpc64le-unknown-linux" {{.*}}"-emit-llvm-bc"
+// CHK-COMMANDS: clang{{.*}}" "-cc1" "-triple" "powerpc64le-unknown-linux" {{.*}}"-emit-llvm-bc" {{.*}}"-disable-llvm-passes"
 // CHK-COMMANDS-SAME: "-fopenmp-targets=powerpc64le-ibm-linux-gnu,x86_64-pc-linux-gnu"
 // CHK-COMMANDS-SAME: "-o" "
 // CHK-COMMANDS-SAME: [[HOSTBC:[^\\/]+\.bc]]" "-x" "c" "
@@ -269,7 +269,7 @@
 // CHK-COMMANDS-ST: clang{{.*}}" "-cc1" "-triple" "powerpc64le-unknown-linux" {{.*}}"-E" {{.*}}"-fopenmp" {{.*}}"-o" "
 // CHK-COMMANDS-ST-SAME: [[HOSTPP:[^\\/]+\.i]]" "-x" "c" "
 // CHK-COMMANDS-ST-SAME: [[INPUT:[^\\/]+\.c]]"
-// CHK-COMMANDS-ST: clang{{.*}}" "-cc1" "-triple" "powerpc64le-unknown-linux" {{.*}}"-emit-llvm-bc" {{.*}}"-fopenmp" {{.*}}"-fopenmp-targets=powerpc64le-ibm-linux-gnu,x86_64-pc-linux-gnu" {{.*}}"-o" "
+// CHK-COMMANDS-ST: clang{{.*}}" "-cc1" "-triple" "powerpc64le-unknown-linux" {{.*}}"-emit-llvm-bc" {{.*}}"-fopenmp" {{.*}}"-disable-llvm-passes" {{.*}}"-fopenmp-targets=powerpc64le-ibm-linux-gnu,x86_64-pc-linux-gnu" {{.*}}"-o" "
 // CHK-COMMANDS-ST-SAME: [[HOSTBC:[^\\/]+\.bc]]" "-x" "cpp-output" "{{.*}}[[HOSTPP]]"
 // CHK-COMMANDS-ST: clang{{.*}}" "-cc1" "-triple" "powerpc64le-unknown-linux" {{.*}}"-S" {{.*}}"-fopenmp" {{.*}}"-o" "
 // CHK-COMMANDS-ST-SAME: [[HOSTASM:[^\\/]+\.s]]" "-x" "ir" "{{.*}}[[HOSTBC]]"
@@ -427,14 +427,14 @@
 // RUN:   | FileCheck -check-prefix=CHK-BUJOBS-ST %s
 
 // Create host BC.
-// CHK-BUJOBS: clang{{.*}}" "-cc1" "-triple" "powerpc64le-unknown-linux" {{.*}}"-emit-llvm-bc"  {{.*}}"-fopenmp" {{.*}}"-fopenmp-targets=powerpc64le-ibm-linux-gnu,x86_64-pc-linux-gnu" {{.*}}"-o" "
+// CHK-BUJOBS: clang{{.*}}" "-cc1" "-triple" "powerpc64le-unknown-linux" {{.*}}"-emit-llvm-bc" {{.*}}"-fopenmp" {{.*}}"-disable-llvm-passes" {{.*}}"-fopenmp-targets=powerpc64le-ibm-linux-gnu,x86_64-pc-linux-gnu" {{.*}}"-o" "
 // CHK-BUJOBS-SAME: [[HOSTBC:[^\\/]+\.bc]]" "-x" "c" "
 // CHK-BUJOBS-SAME: [[INPUT:[^\\/]+\.c]]"
 
 // CHK-BUJOBS-ST: clang{{.*}}" "-cc1" "-triple" "powerpc64le-unknown-linux" {{.*}}"-E"  {{.*}}"-fopenmp" {{.*}}"-o" "
 // CHK-BUJOBS-ST-SAME: [[HOSTPP:[^\\/]+\.i]]" "-x" "c" "
 // CHK-BUJOBS-ST-SAME: [[INPUT:[^\\/]+\.c]]"
-// CHK-BUJOBS-ST: clang{{.*}}" "-cc1" "-triple" "powerpc64le-unknown-linux" {{.*}}"-emit-llvm-bc"  {{.*}}"-fopenmp" {{.*}}"-fopenmp-targets=powerpc64le-ibm-linux-gnu,x86_64-pc-linux-gnu" {{.*}}"-o" "
+// CHK-BUJOBS-ST: clang{{.*}}" "-cc1" "-triple" "powerpc64le-unknown-linux" {{.*}}"-emit-llvm-bc" {{.*}}"-fopenmp" {{.*}}"-disable-llvm-passes" {{.*}}"-fopenmp-targets=powerpc64le-ibm-linux-gnu,x86_64-pc-linux-gnu" {{.*}}"-o" "
 // CHK-BUJOBS-ST-SAME: [[HOSTBC:[^\\/]+\.bc]]" "-x" "cpp-output" "{{.*}}[[HOSTPP]]"
 
 // Create target 1 object.
@@ -493,7 +493,7 @@
 // CHK-UBJOBS-SAME: [[HOSTPP:[^\\/]+\.i]],
 // CHK-UBJOBS-SAME: [[T1PP:[^\\/]+\.i]],
 // CHK-UBJOBS-SAME: [[T2PP:[^\\/]+\.i]]" "-unbundle"
-// CHK-UBJOBS: clang{{.*}}" "-cc1" "-triple" "powerpc64le-unknown-linux" {{.*}}"-emit-llvm-bc"  {{.*}}"-fopenmp" {{.*}}"-fopenmp-targets=powerpc64le-ibm-linux-gnu,x86_64-pc-linux-gnu" {{.*}}"-o" "
+// CHK-UBJOBS: clang{{.*}}" "-cc1" "-triple" "powerpc64le-unknown-linux" {{.*}}"-emit-llvm-bc" {{.*}}"-fopenmp" {{.*}}"-disable-llvm-passes" {{.*}}"-fopenmp-targets=powerpc64le-ibm-linux-gnu,x86_64-pc-linux-gnu" {{.*}}"-o" "
 // CHK-UBJOBS-SAME: [[HOSTBC:[^\\/]+\.bc]]" "-x" "cpp-output" "{{.*}}[[HOSTPP]]"
 // CHK-UBJOBS: clang{{.*}}" "-cc1" "-triple" "powerpc64le-unknown-linux" {{.*}}"-emit-obj" {{.*}}"-fopenmp" {{.*}}"-o" "
 // CHK-UBJOBS-SAME: [[HOSTOBJ:[^\\/]+\.o]]" "-x" "ir" "{{.*}}[[HOSTBC]]"
@@ -502,7 +502,7 @@
 // CHK-UBJOBS-ST-SAME: [[HOSTPP:[^\\/,]+\.i]],
 // CHK-UBJOBS-ST-SAME: [[T1PP:[^\\/,]+\.i]],
 // CHK-UBJOBS-ST-SAME: [[T2PP:[^\\/,]+\.i]]" "-unbundle"
-// CHK-UBJOBS-ST: clang{{.*}}" "-cc1" "-triple" "powerpc64le-unknown-linux" {{.*}}"-emit-llvm-bc"  {{.*}}"-fopenmp" {{.*}}"-fopenmp-targets=powerpc64le-ibm-linux-gnu,x86_64-pc-linux-gnu" {{.*}}"-o" "
+// CHK-UBJOBS-ST: clang{{.*}}" "-cc1" "-triple" "powerpc64le-unknown-linux" {{.*}}"-emit-llvm-bc" {{.*}}"-fopenmp" {{.*}}"-disable-llvm-passes" {{.*}}"-fopenmp-targets=powerpc64le-ibm-linux-gnu,x86_64-pc-linux-gnu" {{.*}}"-o" "
 // CHK-UBJOBS-ST-SAME: [[HOSTBC:[^\\/]+\.bc]]" "-x" "cpp-output" "{{.*}}[[HOSTPP]]"
 // CHK-UBJOBS-ST: clang{{.*}}" "-cc1" "-triple" "powerpc64le-unknown-linux" {{.*}}"-S" {{.*}}"-fopenmp" {{.*}}"-o" "
 // CHK-UBJOBS-ST-SAME: [[HOSTASM:[^\\/]+\.s]]" "-x" "ir" "{{.*}}[[HOSTBC]]"
@@ -607,7 +607,7 @@
 // CHK-UBUJOBS-SAME: [[HOSTPP:[^\\/]+\.i]],
 // CHK-UBUJOBS-SAME: [[T1PP:[^\\/]+\.i]],
 // CHK-UBUJOBS-SAME: [[T2PP:[^\\/]+\.i]]" "-unbundle"
-// CHK-UBUJOBS: clang{{.*}}" "-cc1" "-triple" "powerpc64le-unknown-linux" {{.*}}"-emit-llvm-bc"  {{.*}}"-fopenmp" {{.*}}"-fopenmp-targets=powerpc64le-ibm-linux-gnu,x86_64-pc-linux-gnu" {{.*}}"-o" "
+// CHK-UBUJOBS: clang{{.*}}" "-cc1" "-triple" "powerpc64le-unknown-linux" {{.*}}"-emit-llvm-bc" {{.*}}"-fopenmp" {{.*}}"-disable-llvm-passes" {{.*}}"-fopenmp-targets=powerpc64le-ibm-linux-gnu,x86_64-pc-linux-gnu" {{.*}}"-o" "
 // CHK-UBUJOBS-SAME: [[HOSTBC:[^\\/]+\.bc]]" "-x" "cpp-output" "{{.*}}[[HOSTPP]]"
 
 // CHK-UBUJOBS-ST: clang-offload-bundler{{.*}}" "-type=i" "-targets=host-powerpc64le-unknown-linux,openmp-powerpc64le-ibm-linux-gnu,openmp-x86_64-pc-linux-gnu" "-inputs=
@@ -615,7 +615,7 @@
 // CHK-UBUJOBS-ST-SAME: [[HOSTPP:[^\\/,]+\.i]],
 // CHK-UBUJOBS-ST-SAME: [[T1PP:[^\\/,]+\.i]],
 // CHK-UBUJOBS-ST-SAME: [[T2PP:[^\\/,]+\.i]]" "-unbundle"
-// CHK-UBUJOBS-ST: clang{{.*}}" "-cc1" "-triple" "powerpc64le-unknown-linux" {{.*}}"-emit-llvm-bc"  {{.*}}"-fopenmp" {{.*}}"-fopenmp-targets=powerpc64le-ibm-linux-gnu,x86_64-pc-linux-gnu" {{.*}}"-o" "
+// CHK-UBUJOBS-ST: clang{{.*}}" "-cc1" "-triple" "powerpc64le-unknown-linux" {{.*}}"-emit-llvm-bc" {{.*}}"-fopenmp" {{.*}}"-disable-llvm-passes" {{.*}}"-fopenmp-targets=powerpc64le-ibm-linux-gnu,x86_64-pc-linux-gnu" {{.*}}"-o" "
 // CHK-UBUJOBS-ST-SAME: [[HOSTBC:[^\\/]+\.bc]]" "-x" "cpp-output" "{{.*}}[[HOSTPP]]"
 
 // Create target 1 object.
Index: clang/lib/Driver/ToolChains/Clang.cpp
===================================================================
--- clang/lib/Driver/ToolChains/Clang.cpp
+++ clang/lib/Driver/ToolChains/Clang.cpp
@@ -5788,7 +5788,8 @@
   // FIXME: -fembed-bitcode -save-temps will save optimized bitcode instead of
   // pristine IR generated by the frontend. Ideally, a new compile action should
   // be added so both IR can be captured.
-  if (C.getDriver().isSaveTempsEnabled() &&
+  if ((C.getDriver().isSaveTempsEnabled() ||
+       JA.isHostOffloading(Action::OFK_OpenMP)) &&
       !(C.getDriver().embedBitcodeInObject() && !C.getDriver().isUsingLTO()) &&
       isa<CompileJobAction>(JA))
     CmdArgs.push_back("-disable-llvm-passes");


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