[llvm] r282150 - [RS4GC] Remat in presence of phi and use live value
Philip Reames via llvm-commits
llvm-commits at lists.llvm.org
Tue Sep 27 16:20:47 PDT 2016
Anna,
It looks like the commit message lost the link with the review. Can you
reply with a more full commit message and a link to the review thread?
Philip
On 09/22/2016 06:13 AM, Anna Thomas via llvm-commits wrote:
> Author: annat
> Date: Thu Sep 22 08:13:06 2016
> New Revision: 282150
>
> URL: http://llvm.org/viewvc/llvm-project?rev=282150&view=rev
> Log:
> [RS4GC] Remat in presence of phi and use live value
>
> Summary:
>
> Reviewers:
>
> Subscribers:
>
> Modified:
> llvm/trunk/lib/Transforms/Scalar/RewriteStatepointsForGC.cpp
> llvm/trunk/test/Transforms/RewriteStatepointsForGC/rematerialize-derived-pointers.ll
>
> Modified: llvm/trunk/lib/Transforms/Scalar/RewriteStatepointsForGC.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/RewriteStatepointsForGC.cpp?rev=282150&r1=282149&r2=282150&view=diff
> ==============================================================================
> --- llvm/trunk/lib/Transforms/Scalar/RewriteStatepointsForGC.cpp (original)
> +++ llvm/trunk/lib/Transforms/Scalar/RewriteStatepointsForGC.cpp Thu Sep 22 08:13:06 2016
> @@ -1976,7 +1976,8 @@ static void rematerializeLiveValues(Call
> // Utility function which clones all instructions from "ChainToBase"
> // and inserts them before "InsertBefore". Returns rematerialized value
> // which should be used after statepoint.
> - auto rematerializeChain = [&ChainToBase](Instruction *InsertBefore) {
> + auto rematerializeChain = [&ChainToBase](
> + Instruction *InsertBefore, Value *RootOfChain, Value *AlternateLiveBase) {
> Instruction *LastClonedValue = nullptr;
> Instruction *LastValue = nullptr;
> for (Instruction *Instr: ChainToBase) {
> @@ -1996,13 +1997,24 @@ static void rematerializeLiveValues(Call
> assert(LastValue);
> ClonedValue->replaceUsesOfWith(LastValue, LastClonedValue);
> #ifndef NDEBUG
> - // Assert that cloned instruction does not use any instructions from
> - // this chain other than LastClonedValue
> for (auto OpValue : ClonedValue->operand_values()) {
> + // Assert that cloned instruction does not use any instructions from
> + // this chain other than LastClonedValue
> assert(!is_contained(ChainToBase, OpValue) &&
> "incorrect use in rematerialization chain");
> + // Assert that the cloned instruction does not use the RootOfChain
> + // or the AlternateLiveBase.
> + assert(OpValue != RootOfChain && OpValue != AlternateLiveBase);
> }
> #endif
> + } else {
> + // For the first instruction, replace the use of unrelocated base i.e.
> + // RootOfChain/OrigRootPhi, with the corresponding PHI present in the
> + // live set. They have been proved to be the same PHI nodes. Note
> + // that the *only* use of the RootOfChain in the ChainToBase list is
> + // the first Value in the list.
> + if (RootOfChain != AlternateLiveBase)
> + ClonedValue->replaceUsesOfWith(RootOfChain, AlternateLiveBase);
> }
>
> LastClonedValue = ClonedValue;
> @@ -2017,7 +2029,8 @@ static void rematerializeLiveValues(Call
> if (CS.isCall()) {
> Instruction *InsertBefore = CS.getInstruction()->getNextNode();
> assert(InsertBefore);
> - Instruction *RematerializedValue = rematerializeChain(InsertBefore);
> + Instruction *RematerializedValue = rematerializeChain(
> + InsertBefore, RootOfChain, Info.PointerToBase[LiveValue]);
> Info.RematerializedValues[RematerializedValue] = LiveValue;
> } else {
> InvokeInst *Invoke = cast<InvokeInst>(CS.getInstruction());
> @@ -2027,10 +2040,10 @@ static void rematerializeLiveValues(Call
> Instruction *UnwindInsertBefore =
> &*Invoke->getUnwindDest()->getFirstInsertionPt();
>
> - Instruction *NormalRematerializedValue =
> - rematerializeChain(NormalInsertBefore);
> - Instruction *UnwindRematerializedValue =
> - rematerializeChain(UnwindInsertBefore);
> + Instruction *NormalRematerializedValue = rematerializeChain(
> + NormalInsertBefore, RootOfChain, Info.PointerToBase[LiveValue]);
> + Instruction *UnwindRematerializedValue = rematerializeChain(
> + UnwindInsertBefore, RootOfChain, Info.PointerToBase[LiveValue]);
>
> Info.RematerializedValues[NormalRematerializedValue] = LiveValue;
> Info.RematerializedValues[UnwindRematerializedValue] = LiveValue;
>
> Modified: llvm/trunk/test/Transforms/RewriteStatepointsForGC/rematerialize-derived-pointers.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/RewriteStatepointsForGC/rematerialize-derived-pointers.ll?rev=282150&r1=282149&r2=282150&view=diff
> ==============================================================================
> --- llvm/trunk/test/Transforms/RewriteStatepointsForGC/rematerialize-derived-pointers.ll (original)
> +++ llvm/trunk/test/Transforms/RewriteStatepointsForGC/rematerialize-derived-pointers.ll Thu Sep 22 08:13:06 2016
> @@ -285,7 +285,7 @@ merge:
> ; CHECK: %statepoint_token = call token (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint
> ; CHECK: %basephi.base.relocated = call coldcc i8 addrspace(1)* @llvm.experimental.gc.relocate.p1i8(token %statepoint_token, i32 7, i32 7) ; (%basephi.base, %basephi.base)
> ; CHECK: %basephi.base.relocated.casted = bitcast i8 addrspace(1)* %basephi.base.relocated to i32 addrspace(1)*
> - ; CHECK: %ptr.gep.remat = getelementptr i32, i32 addrspace(1)* %basephi, i32 15
> + ; CHECK: %ptr.gep.remat = getelementptr i32, i32 addrspace(1)* %basephi.base.relocated.casted, i32 15
> ; CHECK: call void @use_obj32(i32 addrspace(1)* %ptr.gep.remat)
>
>
> @@ -296,3 +296,35 @@ merge:
> call void @use_obj32(i32 addrspace(1)* %ptr.gep)
> ret void
> }
> +
> +
> +define void @test_intersecting_chains_with_phi(i1 %cond) gc "statepoint-example" {
> +; CHECK-LABEL: test_intersecting_chains_with_phi
> +entry:
> + %base1 = call i32 addrspace(1)* @new_instance()
> + %base2 = call i32 addrspace(1)* @new_instance()
> + br i1 %cond, label %here, label %there
> +
> +here:
> + br label %merge
> +
> +there:
> + br label %merge
> +
> +merge:
> + %basephi = phi i32 addrspace(1)* [ %base1, %here ], [ %base2, %there ]
> + %ptr.gep = getelementptr i32, i32 addrspace(1)* %basephi, i32 15
> + %ptr.cast = bitcast i32 addrspace(1)* %ptr.gep to i64 addrspace(1)*
> + %ptr.cast2 = bitcast i32 addrspace(1)* %ptr.gep to i16 addrspace(1)*
> + call void @do_safepoint() [ "deopt"() ]
> + ; CHECK: statepoint
> + ; CHECK: %ptr.gep.remat1 = getelementptr i32, i32 addrspace(1)* %basephi.base.relocated.casted, i32 15
> + ; CHECK: %ptr.cast.remat = bitcast i32 addrspace(1)* %ptr.gep.remat1 to i64 addrspace(1)*
> + ; CHECK: %ptr.gep.remat = getelementptr i32, i32 addrspace(1)* %basephi.base.relocated.casted, i32 15
> + ; CHECK: %ptr.cast2.remat = bitcast i32 addrspace(1)* %ptr.gep.remat to i16 addrspace(1)*
> + ; CHECK: call void @use_obj64(i64 addrspace(1)* %ptr.cast.remat)
> + ; CHECK: call void @use_obj16(i16 addrspace(1)* %ptr.cast2.remat)
> + call void @use_obj64(i64 addrspace(1)* %ptr.cast)
> + call void @use_obj16(i16 addrspace(1)* %ptr.cast2)
> + ret void
> +}
>
>
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