[PATCH] D98728: [LICM] Fix a bug involving sinking of instructions w/token operands

[Philip Reames via Phabricator via llvm-commits]

reames created this revision.
reames added reviewers: skatkov, fhahn, nikic.
Herald added subscribers: dantrushin, asbirlea, hiraditya, mcrosier.
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It is not legal to form a phi node with token type.  The generic LCSSA construction code handles this correctly - by not forming LCSSA for such cases - but the adhoc fixup implementation in LICM did not.

This was noticed in the context of PR49607, but can be demonstrated on ToT with the tweaked test case.  This is not specific to gc.relocate btw, it also applies to usage of the preallocated family of intrinsics as well.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D98728

Files:
  llvm/lib/Transforms/Scalar/LICM.cpp
  llvm/test/Transforms/LICM/gc-relocate.ll


Index: llvm/test/Transforms/LICM/gc-relocate.ll
===================================================================
--- llvm/test/Transforms/LICM/gc-relocate.ll
+++ llvm/test/Transforms/LICM/gc-relocate.ll
@@ -10,18 +10,17 @@
 ; CHECK-NEXT:    br label [[BB1:%.*]]
 ; CHECK:       bb1:
 ; CHECK-NEXT:    [[TMP:%.*]] = call token (i64, i32, i32 (i32, i8 addrspace(1)*, i32, i32, i32)*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_i32i32p1i8i32i32i32f(i64 1, i32 16, i32 (i32, i8 addrspace(1)*, i32, i32, i32)* nonnull @zot, i32 5, i32 0, i32 undef, i8 addrspace(1)* undef, i32 undef, i32 undef, i32 undef, i32 0, i32 0) [ "deopt"(i32 0, i32 0, i32 0, i32 235, i32 3, i32 32, i32 0, i32 0, i8 addrspace(1)* undef, i32 3, i32 undef, i32 3, float undef, i32 0, i8 addrspace(1)* undef, i32 7, i8* null, i32 3, i32 undef, i32 3, i32 undef, i32 3, i32 undef, i32 3, i32 undef, i32 3, i32 undef, i32 3, i32 undef, i32 3, i32 undef, i32 3, i32 undef, i32 3, i32 undef, i32 3, i32 undef, i32 3, i32 undef, i32 3, i32 undef, i32 3, i32 undef, i32 0, i8 addrspace(1)* undef, i32 4, double undef, i32 7, i8* null, i32 0, i8 addrspace(1)* undef, i32 3, float undef, i32 0, i8 addrspace(1)* undef, i32 0, i8 addrspace(1)* undef, i32 0, i8 addrspace(1)* undef, i32 0, i8 addrspace(1)* undef, i32 0, i8 addrspace(1)* undef, i32 0, i8 addrspace(1)* null, i32 3, i32 -15108, i32 7, i8* null, i32 7, i8* null, i32 7, i8* null, i32 7, i8* null, i32 7, i8* null), "gc-live"(i8 addrspace(1)* [[ARG:%.*]]) ]
-; CHECK-NEXT:    [[RES:%.*]] = call coldcc i8 addrspace(1)* @llvm.experimental.gc.relocate.p1i8(token [[TMP]], i32 0, i32 0)
 ; CHECK-NEXT:    br i1 false, label [[BB1]], label [[BB2:%.*]]
 ; CHECK:       bb2:
-; CHECK-NEXT:    [[RES_LCSSA:%.*]] = phi i8 addrspace(1)* [ [[RES]], [[BB1]] ]
-; CHECK-NEXT:    ret i8 addrspace(1)* [[RES_LCSSA]]
+; CHECK-NEXT:    [[RES_LE:%.*]] = call coldcc i8 addrspace(1)* @llvm.experimental.gc.relocate.p1i8(token [[TMP]], i32 0, i32 0) #[[ATTR2:[0-9]+]]
+; CHECK-NEXT:    ret i8 addrspace(1)* [[RES_LE]]
 ;
 bb:
   br label %bb1
 
 bb1:
   %tmp = call token (i64, i32, i32 (i32, i8 addrspace(1)*, i32, i32, i32)*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_i32i32p1i8i32i32i32f(i64 1, i32 16, i32 (i32, i8 addrspace(1)*, i32, i32, i32)* nonnull @zot, i32 5, i32 0, i32 undef, i8 addrspace(1)* undef, i32 undef, i32 undef, i32 undef, i32 0, i32 0) [ "deopt"(i32 0, i32 0, i32 0, i32 235, i32 3, i32 32, i32 0, i32 0, i8 addrspace(1)* undef, i32 3, i32 undef, i32 3, float undef, i32 0, i8 addrspace(1)* undef, i32 7, i8* null, i32 3, i32 undef, i32 3, i32 undef, i32 3, i32 undef, i32 3, i32 undef, i32 3, i32 undef, i32 3, i32 undef, i32 3, i32 undef, i32 3, i32 undef, i32 3, i32 undef, i32 3, i32 undef, i32 3, i32 undef, i32 3, i32 undef, i32 3, i32 undef, i32 0, i8 addrspace(1)* undef, i32 4, double undef, i32 7, i8* null, i32 0, i8 addrspace(1)* undef, i32 3, float undef, i32 0, i8 addrspace(1)* undef, i32 0, i8 addrspace(1)* undef, i32 0, i8 addrspace(1)* undef, i32 0, i8 addrspace(1)* undef, i32 0, i8 addrspace(1)* undef, i32 0, i8 addrspace(1)* null, i32 3, i32 -15108, i32 7, i8* null, i32 7, i8* null, i32 7, i8* null, i32 7, i8* null, i32 7, i8* null), "gc-live"(i8 addrspace(1)* %arg) ]
-  %res = call coldcc i8 addrspace(1)* @llvm.experimental.gc.relocate.p1i8(token %tmp, i32 0, i32 0)
+  %res = call coldcc i8 addrspace(1)* @llvm.experimental.gc.relocate.p1i8(token %tmp, i32 0, i32 0) readnone
   br i1 undef, label %bb1, label %bb2
 
 bb2:
Index: llvm/lib/Transforms/Scalar/LICM.cpp
===================================================================
--- llvm/lib/Transforms/Scalar/LICM.cpp
+++ llvm/lib/Transforms/Scalar/LICM.cpp
@@ -1512,7 +1512,7 @@
   for (Use &Op : New->operands())
     if (Instruction *OInst = dyn_cast<Instruction>(Op))
       if (Loop *OLoop = LI->getLoopFor(OInst->getParent()))
-        if (!OLoop->contains(&PN)) {
+        if (!OLoop->contains(&PN) && !Op->getType()->isTokenTy()) {
           PHINode *OpPN =
               PHINode::Create(OInst->getType(), PN.getNumIncomingValues(),
                               OInst->getName() + ".lcssa", &ExitBlock.front());
@@ -1859,7 +1859,7 @@
   Value *maybeInsertLCSSAPHI(Value *V, BasicBlock *BB) const {
     if (Instruction *I = dyn_cast<Instruction>(V))
       if (Loop *L = LI.getLoopFor(I->getParent()))
-        if (!L->contains(BB)) {
+        if (!L->contains(BB) && !I->getType()->isTokenTy()) {
           // We need to create an LCSSA PHI node for the incoming value and
           // store that.
           PHINode *PN = PHINode::Create(I->getType(), PredCache.size(BB),


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