Revert "[DFAJumpThreading] Enable DFAJumpThread by default." #167352
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This reverts commit 0ba7bfc.
XChy
approved these changes
Nov 10, 2025
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@llvm/pr-subscribers-backend-amdgpu Author: Petr Hosek (petrhosek) ChangesReverts llvm/llvm-project#157646, DFAJumpThread is causing miscompiles when building Clang with LTO and PGO, see llvm/llvm-project#166868 for details. Full diff: https://github.com/llvm/llvm-project/pull/167352.diff 9 Files Affected:
diff --git a/llvm/lib/Passes/PassBuilderPipelines.cpp b/llvm/lib/Passes/PassBuilderPipelines.cpp
index 2fe963b3b68d9..dd73c04959732 100644
--- a/llvm/lib/Passes/PassBuilderPipelines.cpp
+++ b/llvm/lib/Passes/PassBuilderPipelines.cpp
@@ -228,7 +228,7 @@ static cl::opt<bool> EnableLoopHeaderDuplication(
static cl::opt<bool>
EnableDFAJumpThreading("enable-dfa-jump-thread",
cl::desc("Enable DFA jump threading"),
- cl::init(true), cl::Hidden);
+ cl::init(false), cl::Hidden);
static cl::opt<bool>
EnableHotColdSplit("hot-cold-split",
diff --git a/llvm/test/CodeGen/AMDGPU/reg-coalescer-subreg-liveness.mir b/llvm/test/CodeGen/AMDGPU/reg-coalescer-subreg-liveness.mir
index 381cb8c9d1047..f098618018839 100644
--- a/llvm/test/CodeGen/AMDGPU/reg-coalescer-subreg-liveness.mir
+++ b/llvm/test/CodeGen/AMDGPU/reg-coalescer-subreg-liveness.mir
@@ -16,11 +16,11 @@ body: |
; CHECK-NEXT: [[COPY:%[0-9]+]]:sgpr_64 = COPY $sgpr4_sgpr5
; CHECK-NEXT: undef [[S_LOAD_DWORD_IMM:%[0-9]+]].sub1:sgpr_128 = S_LOAD_DWORD_IMM [[COPY]], 0, 0 :: (dereferenceable invariant load (s32), align 16, addrspace 4)
; CHECK-NEXT: undef [[S_MOV_B32_:%[0-9]+]].sub0:sgpr_128 = S_MOV_B32 1
+ ; CHECK-NEXT: [[S_LOAD_DWORD_IMM:%[0-9]+]].sub2:sgpr_128 = S_MOV_B32 0
; CHECK-NEXT: undef [[S_MOV_B32_1:%[0-9]+]].sub0:sgpr_256 = S_MOV_B32 0
; CHECK-NEXT: TENSOR_LOAD_TO_LDS_D2 [[S_MOV_B32_]], [[S_MOV_B32_1]], 0, 0, implicit-def dead $tensorcnt, implicit $exec, implicit $tensorcnt
; CHECK-NEXT: [[S_LOAD_DWORD_IMM:%[0-9]+]].sub0:sgpr_128 = S_MOV_B32 1
; CHECK-NEXT: [[S_MOV_B32_:%[0-9]+]].sub1:sgpr_128 = COPY [[S_MOV_B32_]].sub0
- ; CHECK-NEXT: [[S_LOAD_DWORD_IMM:%[0-9]+]].sub2:sgpr_128 = S_MOV_B32 0
; CHECK-NEXT: {{ $}}
; CHECK-NEXT: bb.1:
; CHECK-NEXT: successors: %bb.1(0x40000000), %bb.2(0x40000000)
diff --git a/llvm/test/Other/new-pm-defaults.ll b/llvm/test/Other/new-pm-defaults.ll
index b59d4cf6af998..1f437a662cc96 100644
--- a/llvm/test/Other/new-pm-defaults.ll
+++ b/llvm/test/Other/new-pm-defaults.ll
@@ -208,7 +208,6 @@
; CHECK-O-NEXT: Running analysis: DemandedBitsAnalysis
; CHECK-O-NEXT: Running pass: InstCombinePass
; CHECK-EP-PEEPHOLE-NEXT: Running pass: NoOpFunctionPass
-; CHECK-O23SZ-NEXT: Running pass: DFAJumpThreadingPass
; CHECK-O23SZ-NEXT: Running pass: JumpThreadingPass
; CHECK-O23SZ-NEXT: Running analysis: LazyValueAnalysis
; CHECK-O23SZ-NEXT: Running pass: CorrelatedValuePropagationPass
diff --git a/llvm/test/Other/new-pm-thinlto-postlink-defaults.ll b/llvm/test/Other/new-pm-thinlto-postlink-defaults.ll
index c1d8b42505c84..2d8b8f1b22091 100644
--- a/llvm/test/Other/new-pm-thinlto-postlink-defaults.ll
+++ b/llvm/test/Other/new-pm-thinlto-postlink-defaults.ll
@@ -133,7 +133,6 @@
; CHECK-O-NEXT: Running pass: BDCEPass
; CHECK-O-NEXT: Running analysis: DemandedBitsAnalysis
; CHECK-O-NEXT: Running pass: InstCombinePass
-; CHECK-O23SZ-NEXT: Running pass: DFAJumpThreadingPass
; CHECK-O23SZ-NEXT: Running pass: JumpThreadingPass
; CHECK-O23SZ-NEXT: Running analysis: LazyValueAnalysis
; CHECK-O23SZ-NEXT: Running pass: CorrelatedValuePropagationPass
diff --git a/llvm/test/Other/new-pm-thinlto-postlink-pgo-defaults.ll b/llvm/test/Other/new-pm-thinlto-postlink-pgo-defaults.ll
index 45f090252eaf7..7cacc17c7ab9a 100644
--- a/llvm/test/Other/new-pm-thinlto-postlink-pgo-defaults.ll
+++ b/llvm/test/Other/new-pm-thinlto-postlink-pgo-defaults.ll
@@ -118,7 +118,6 @@
; CHECK-O-NEXT: Running pass: BDCEPass
; CHECK-O-NEXT: Running analysis: DemandedBitsAnalysis
; CHECK-O-NEXT: Running pass: InstCombinePass
-; CHECK-O23SZ-NEXT: Running pass: DFAJumpThreadingPass
; CHECK-O23SZ-NEXT: Running pass: JumpThreadingPass
; CHECK-O23SZ-NEXT: Running analysis: LazyValueAnalysis
; CHECK-O23SZ-NEXT: Running pass: CorrelatedValuePropagationPass
diff --git a/llvm/test/Other/new-pm-thinlto-postlink-samplepgo-defaults.ll b/llvm/test/Other/new-pm-thinlto-postlink-samplepgo-defaults.ll
index 4c330f44d30cc..ef6cd8354ae3d 100644
--- a/llvm/test/Other/new-pm-thinlto-postlink-samplepgo-defaults.ll
+++ b/llvm/test/Other/new-pm-thinlto-postlink-samplepgo-defaults.ll
@@ -127,7 +127,6 @@
; CHECK-O-NEXT: Running pass: BDCEPass
; CHECK-O-NEXT: Running analysis: DemandedBitsAnalysis
; CHECK-O-NEXT: Running pass: InstCombinePass
-; CHECK-O23SZ-NEXT: Running pass: DFAJumpThreadingPass
; CHECK-O23SZ-NEXT: Running pass: JumpThreadingPass
; CHECK-O23SZ-NEXT: Running analysis: LazyValueAnalysis
; CHECK-O23SZ-NEXT: Running pass: CorrelatedValuePropagationPass
diff --git a/llvm/test/Other/new-pm-thinlto-prelink-defaults.ll b/llvm/test/Other/new-pm-thinlto-prelink-defaults.ll
index b61edc805108d..dd6acd2c51ee7 100644
--- a/llvm/test/Other/new-pm-thinlto-prelink-defaults.ll
+++ b/llvm/test/Other/new-pm-thinlto-prelink-defaults.ll
@@ -165,7 +165,6 @@
; CHECK-O-NEXT: Running pass: BDCEPass
; CHECK-O-NEXT: Running analysis: DemandedBitsAnalysis
; CHECK-O-NEXT: Running pass: InstCombinePass
-; CHECK-O23SZ-NEXT: Running pass: DFAJumpThreadingPass
; CHECK-O23SZ-NEXT: Running pass: JumpThreadingPass
; CHECK-O23SZ-NEXT: Running analysis: LazyValueAnalysis
; CHECK-O23SZ-NEXT: Running pass: CorrelatedValuePropagationPass
diff --git a/llvm/test/Other/new-pm-thinlto-prelink-pgo-defaults.ll b/llvm/test/Other/new-pm-thinlto-prelink-pgo-defaults.ll
index acf8c053d0f82..ee054527e20bd 100644
--- a/llvm/test/Other/new-pm-thinlto-prelink-pgo-defaults.ll
+++ b/llvm/test/Other/new-pm-thinlto-prelink-pgo-defaults.ll
@@ -167,7 +167,6 @@
; CHECK-O-NEXT: Running pass: BDCEPass
; CHECK-O-NEXT: Running analysis: DemandedBitsAnalysis
; CHECK-O-NEXT: Running pass: InstCombinePass
-; CHECK-O23SZ-NEXT: Running pass: DFAJumpThreadingPass
; CHECK-O23SZ-NEXT: Running pass: JumpThreadingPass
; CHECK-O23SZ-NEXT: Running analysis: LazyValueAnalysis
; CHECK-O23SZ-NEXT: Running pass: CorrelatedValuePropagationPass
diff --git a/llvm/test/Other/new-pm-thinlto-prelink-samplepgo-defaults.ll b/llvm/test/Other/new-pm-thinlto-prelink-samplepgo-defaults.ll
index 6b3c5ca7605de..fd95e94f3c8b9 100644
--- a/llvm/test/Other/new-pm-thinlto-prelink-samplepgo-defaults.ll
+++ b/llvm/test/Other/new-pm-thinlto-prelink-samplepgo-defaults.ll
@@ -131,7 +131,6 @@
; CHECK-O-NEXT: Running pass: BDCEPass
; CHECK-O-NEXT: Running analysis: DemandedBitsAnalysis
; CHECK-O-NEXT: Running pass: InstCombinePass
-; CHECK-O23SZ-NEXT: Running pass: DFAJumpThreadingPass
; CHECK-O23SZ-NEXT: Running pass: JumpThreadingPass
; CHECK-O23SZ-NEXT: Running analysis: LazyValueAnalysis
; CHECK-O23SZ-NEXT: Running pass: CorrelatedValuePropagationPass
|
XChy
deleted the
revert-157646-OpenXiangShan/default-enable-DFAJumpThreading
branch
Contributor
|
@XChy When you have fixed the reported issue and go to reland the enablement, can you ping me for a review? I'd like to do some internal qualification on this before relanding. We've seen quite a bit of breakage due to this change. |
Member
Sure, I am still investigating it now though..
Surprisingly, the problem is so severe. Could you provide some test cases or examples, since I have only met this issue since its enablement? |
Contributor
I'd prefer to wait for the existing issues to be fixed before spending the resources evaluating this change on our entire codebase. |
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Reverts #157646, DFAJumpThread is causing miscompiles when building Clang with LTO and PGO, see #166868 for details.