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[GuardUtils] Revert llvm::isWidenableBranch change #66411

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Merged
merged 1 commit into from
Sep 20, 2023
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[GuardUtils] Revert llvm::isWidenableBranch change #66411

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5 changes: 4 additions & 1 deletion llvm/lib/Analysis/GuardUtils.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -24,7 +24,10 @@ bool llvm::isWidenableCondition(const Value *V) {
}

bool llvm::isWidenableBranch(const User *U) {
return extractWidenableCondition(U) != nullptr;
Value *Condition, *WidenableCondition;
BasicBlock *GuardedBB, *DeoptBB;
return parseWidenableBranch(U, Condition, WidenableCondition, GuardedBB,
DeoptBB);
}

bool llvm::isGuardAsWidenableBranch(const User *U) {
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50 changes: 50 additions & 0 deletions llvm/test/Transforms/LoopPredication/basic_widenable_branch_guards.ll
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Expand Up @@ -2144,6 +2144,56 @@ exit: ; preds = %guarded, %entry
ret i32 %result
}

; TODO: Support widenable branch in the form of br((wc and cond0) and cond1)
; At present LoopPredication assumes the form of br(wc && (...)) only.
define i32 @wc_deep_in_expression_tree(i1 %cond0, i1 %cond1, i32 %limit) {
; CHECK-LABEL: @wc_deep_in_expression_tree(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[WC:%.*]] = call i1 @llvm.experimental.widenable.condition()
; CHECK-NEXT: [[AND0:%.*]] = and i1 [[WC]], [[COND0:%.*]]
; CHECK-NEXT: [[AND1:%.*]] = and i1 [[AND0]], [[COND1:%.*]]
; CHECK-NEXT: br i1 [[AND1]], label [[LOOP_PREHEADER:%.*]], label [[DEOPT:%.*]]
; CHECK: loop.preheader:
; CHECK-NEXT: br label [[LOOP:%.*]]
; CHECK: loop:
; CHECK-NEXT: [[IV:%.*]] = phi i32 [ [[IV_NEXT:%.*]], [[GUARDED:%.*]] ], [ 0, [[LOOP_PREHEADER]] ]
; CHECK-NEXT: [[GUARD_COND:%.*]] = icmp sgt i32 [[IV]], 100
; CHECK-NEXT: br i1 [[GUARD_COND]], label [[DEOPT_LOOPEXIT:%.*]], label [[GUARDED]]
; CHECK: guarded:
; CHECK-NEXT: [[IV_NEXT]] = add i32 [[IV]], 1
; CHECK-NEXT: [[EXIT_COND:%.*]] = icmp ult i32 [[IV]], [[LIMIT:%.*]]
; CHECK-NEXT: br i1 [[EXIT_COND]], label [[LOOP]], label [[EXIT:%.*]]
; CHECK: deopt.loopexit:
; CHECK-NEXT: br label [[DEOPT]]
; CHECK: deopt:
; CHECK-NEXT: [[DEOPTCALL:%.*]] = call i32 (...) @llvm.experimental.deoptimize.i32(i32 9) [ "deopt"() ]
; CHECK-NEXT: ret i32 [[DEOPTCALL]]
; CHECK: exit:
; CHECK-NEXT: ret i32 0
;
entry:
%wc = call i1 @llvm.experimental.widenable.condition()
%and0 = and i1 %wc, %cond0
%and1 = and i1 %and0, %cond1
br i1 %and1, label %loop, label %deopt

loop:
%iv = phi i32 [ %iv.next, %guarded ], [ 0, %entry ]
%guard.cond = icmp sgt i32 %iv, 100
br i1 %guard.cond, label %deopt, label %guarded

guarded:
%iv.next = add i32 %iv, 1
%exit.cond = icmp ult i32 %iv, %limit
br i1 %exit.cond, label %loop, label %exit

deopt:
%deoptcall = call i32 (...) @llvm.experimental.deoptimize.i32(i32 9) [ "deopt"() ]
ret i32 %deoptcall
exit:
ret i32 0
}

declare i32 @llvm.experimental.deoptimize.i32(...)

; Function Attrs: inaccessiblememonly nounwind
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