[llvm] 5e442a5 - [Attributor][NFC] Do not delete dead blocks but "clear" them
Johannes Doerfert via llvm-commits
llvm-commits at lists.llvm.org
Wed Oct 30 22:10:16 PDT 2019
Author: Johannes Doerfert
Date: 2019-10-31T00:09:50-05:00
New Revision: 5e442a51bce73f3e69eef022674acfb28224619d
URL: https://github.com/llvm/llvm-project/commit/5e442a51bce73f3e69eef022674acfb28224619d
DIFF: https://github.com/llvm/llvm-project/commit/5e442a51bce73f3e69eef022674acfb28224619d.diff
LOG: [Attributor][NFC] Do not delete dead blocks but "clear" them
Deleting blocks will require us to deal with dead edges, e.g.,
`br i1 false, label %live, label %dead`
explicitly. For now we just clear the blocks and move on.
This will be revisited once we actually fold branches.
Added:
Modified:
llvm/lib/Transforms/IPO/Attributor.cpp
llvm/test/Transforms/FunctionAttrs/liveness.ll
Removed:
################################################################################
diff --git a/llvm/lib/Transforms/IPO/Attributor.cpp b/llvm/lib/Transforms/IPO/Attributor.cpp
index 11a4939da781..129eb1976745 100644
--- a/llvm/lib/Transforms/IPO/Attributor.cpp
+++ b/llvm/lib/Transforms/IPO/Attributor.cpp
@@ -4644,9 +4644,12 @@ ChangeStatus Attributor::run(Module &M) {
SmallVector<BasicBlock *, 8> ToBeDeletedBBs;
ToBeDeletedBBs.reserve(NumDeadBlocks);
ToBeDeletedBBs.append(ToBeDeletedBlocks.begin(), ToBeDeletedBlocks.end());
- DeleteDeadBlocks(ToBeDeletedBBs);
- STATS_DECLTRACK(AAIsDead, BasicBlock,
- "Number of dead basic blocks deleted.");
+ // Actually we do not delete the blocks but squash them into a single
+ // unreachable but untangling branches that jump here is something we need
+ // to do in a more generic way.
+ DetatchDeadBlocks(ToBeDeletedBBs, nullptr);
+ STATS_DECL(AAIsDead, BasicBlock, "Number of dead basic blocks deleted.");
+ BUILD_STAT_NAME(AAIsDead, BasicBlock) += ToBeDeletedBlocks.size();
}
STATS_DECL(AAIsDead, Function, "Number of dead functions deleted.");
diff --git a/llvm/test/Transforms/FunctionAttrs/liveness.ll b/llvm/test/Transforms/FunctionAttrs/liveness.ll
index e1bcb31d288a..f029f9476b75 100644
--- a/llvm/test/Transforms/FunctionAttrs/liveness.ll
+++ b/llvm/test/Transforms/FunctionAttrs/liveness.ll
@@ -56,7 +56,6 @@ entry:
call void @no_return_call()
; CHECK: call void @no_return_call()
; CHECK-NEXT: unreachable
- ; CHECK-NEXT: }
call i32 @dead_internal_func(i32 10)
%cmp = icmp eq i32 %a, 0
br i1 %cmp, label %cond.true, label %cond.false
@@ -130,7 +129,6 @@ cond.false: ; preds = %entry
; CHECK: call void @no_return_call()
; CHECK-NEXT: unreachable
call i32 @dead_internal_func(i32 10)
- ; CHECK-NEXT: }
%call1 = call i32 @bar()
br label %cond.end
@@ -526,7 +524,6 @@ define linkonce_odr void @non_exact3() {
; CHECK-NEXT: call void @non_dead_d15()
; CHECK-NEXT: %nr = call i32 @foo_noreturn()
; CHECK-NEXT: unreachable
-; CHECK-NEXT: }
define internal void @non_dead_a0() { ret void }
define internal void @non_dead_a1() { ret void }
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