[llvm] r292625 - AArch64LoadStoreOptimizer: Update kill flags when merging stores
Matthias Braun via llvm-commits
llvm-commits at lists.llvm.org
Fri Jan 20 10:04:27 PST 2017
Author: matze
Date: Fri Jan 20 12:04:27 2017
New Revision: 292625
URL: http://llvm.org/viewvc/llvm-project?rev=292625&view=rev
Log:
AArch64LoadStoreOptimizer: Update kill flags when merging stores
Kill flags need to be updated correctly when moving stores up/down to
form store pair instructions.
Those invalid flags have been ignored before but as of r290014 they are
recognized when using -mllvm -verify-machineinstrs.
Also simplifies test/CodeGen/AArch64/ldst-opt-dbg-limit.mir, renames it
to ldst-opt.mir test and adds a new tests for this change.
Differential Revision: https://reviews.llvm.org/D28875
Added:
llvm/trunk/test/CodeGen/AArch64/ldst-opt.mir
Removed:
llvm/trunk/test/CodeGen/AArch64/ldst-opt-dbg-limit.mir
Modified:
llvm/trunk/lib/Target/AArch64/AArch64LoadStoreOptimizer.cpp
Modified: llvm/trunk/lib/Target/AArch64/AArch64LoadStoreOptimizer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/AArch64/AArch64LoadStoreOptimizer.cpp?rev=292625&r1=292624&r2=292625&view=diff
==============================================================================
--- llvm/trunk/lib/Target/AArch64/AArch64LoadStoreOptimizer.cpp (original)
+++ llvm/trunk/lib/Target/AArch64/AArch64LoadStoreOptimizer.cpp Fri Jan 20 12:04:27 2017
@@ -687,9 +687,30 @@ AArch64LoadStoreOpt::mergePairedInsns(Ma
MachineInstrBuilder MIB;
DebugLoc DL = I->getDebugLoc();
MachineBasicBlock *MBB = I->getParent();
+ MachineOperand RegOp0 = getLdStRegOp(*RtMI);
+ MachineOperand RegOp1 = getLdStRegOp(*Rt2MI);
+ // Kill flags may become invalid when moving stores for pairing.
+ if (RegOp0.isUse()) {
+ if (!MergeForward) {
+ // Clear kill flags on store if moving upwards. Example:
+ // STRWui %w0, ...
+ // USE %w1
+ // STRWui kill %w1 ; need to clear kill flag when moving STRWui upwards
+ RegOp0.setIsKill(false);
+ RegOp1.setIsKill(false);
+ } else {
+ // Clear kill flags of the first stores register. Example:
+ // STRWui %w1, ...
+ // USE kill %w1 ; need to clear kill flag when moving STRWui downwards
+ // STRW %w0
+ unsigned Reg = getLdStRegOp(*I).getReg();
+ for (MachineInstr &MI : make_range(std::next(I), Paired))
+ MI.clearRegisterKills(Reg, TRI);
+ }
+ }
MIB = BuildMI(*MBB, InsertionPoint, DL, TII->get(getMatchingPairOpcode(Opc)))
- .add(getLdStRegOp(*RtMI))
- .add(getLdStRegOp(*Rt2MI))
+ .add(RegOp0)
+ .add(RegOp1)
.add(BaseRegOp)
.addImm(OffsetImm)
.setMemRefs(I->mergeMemRefsWith(*Paired));
Removed: llvm/trunk/test/CodeGen/AArch64/ldst-opt-dbg-limit.mir
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AArch64/ldst-opt-dbg-limit.mir?rev=292624&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/AArch64/ldst-opt-dbg-limit.mir (original)
+++ llvm/trunk/test/CodeGen/AArch64/ldst-opt-dbg-limit.mir (removed)
@@ -1,133 +0,0 @@
-# RUN: llc -run-pass=aarch64-ldst-opt %s -o - 2>&1 | FileCheck %s
---- |
- target datalayout = "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128"
- target triple = "aarch64--linux-gnu"
-
- ; Function Attrs: nounwind
- define i16 @promote-load-from-store(i32* %dst, i32 %x) #0 {
- store i32 %x, i32* %dst
- %dst16 = bitcast i32* %dst to i16*
- %dst1 = getelementptr inbounds i16, i16* %dst16, i32 1
- %x16 = load i16, i16* %dst1
- ret i16 %x16
- }
-
- ; Function Attrs: nounwind
- define void @store-pair(i32* %dst, i32 %x, i32 %y) #0 {
- %dst01 = bitcast i32* %dst to i32*
- %dst1 = getelementptr inbounds i32, i32* %dst, i32 1
- store i32 %x, i32* %dst01
- store i32 %x, i32* %dst1
- ret void
- }
-
- attributes #0 = { nounwind }
-
-...
----
-name: promote-load-from-store
-alignment: 2
-exposesReturnsTwice: false
-tracksRegLiveness: true
-liveins:
- - { reg: '%x0' }
- - { reg: '%w1' }
-frameInfo:
- isFrameAddressTaken: false
- isReturnAddressTaken: false
- hasStackMap: false
- hasPatchPoint: false
- stackSize: 0
- offsetAdjustment: 0
- maxAlignment: 0
- adjustsStack: false
- hasCalls: false
- maxCallFrameSize: 0
- hasOpaqueSPAdjustment: false
- hasVAStart: false
- hasMustTailInVarArgFunc: false
-body: |
- bb.0 (%ir-block.0):
- liveins: %w1, %x0, %lr
-
- STRWui killed %w1, %x0, 0 :: (store 4 into %ir.dst)
- CFI_INSTRUCTION 0
- CFI_INSTRUCTION 0
- CFI_INSTRUCTION 0
- CFI_INSTRUCTION 0
- CFI_INSTRUCTION 0
- CFI_INSTRUCTION 0
- CFI_INSTRUCTION 0
- CFI_INSTRUCTION 0
- CFI_INSTRUCTION 0
- CFI_INSTRUCTION 0
- CFI_INSTRUCTION 0
- CFI_INSTRUCTION 0
- CFI_INSTRUCTION 0
- CFI_INSTRUCTION 0
- CFI_INSTRUCTION 0
- CFI_INSTRUCTION 0
- CFI_INSTRUCTION 0
- CFI_INSTRUCTION 0
- CFI_INSTRUCTION 0
- CFI_INSTRUCTION 0
- %w0 = LDRHHui killed %x0, 1 :: (load 2 from %ir.dst1)
- RET %lr, implicit %w0
-
-...
-# CHECK-LABEL: name: promote-load-from-store
-# CHECK: STRWui %w1
-# CHECK: UBFMWri %w1
----
-name: store-pair
-alignment: 2
-exposesReturnsTwice: false
-tracksRegLiveness: true
-liveins:
- - { reg: '%x0' }
- - { reg: '%w1' }
-frameInfo:
- isFrameAddressTaken: false
- isReturnAddressTaken: false
- hasStackMap: false
- hasPatchPoint: false
- stackSize: 0
- offsetAdjustment: 0
- maxAlignment: 0
- adjustsStack: false
- hasCalls: false
- maxCallFrameSize: 0
- hasOpaqueSPAdjustment: false
- hasVAStart: false
- hasMustTailInVarArgFunc: false
-body: |
- bb.0 (%ir-block.0):
- liveins: %w1, %x0, %lr
-
- STRWui %w1, %x0, 0 :: (store 4 into %ir.dst01)
- CFI_INSTRUCTION 0
- CFI_INSTRUCTION 0
- CFI_INSTRUCTION 0
- CFI_INSTRUCTION 0
- CFI_INSTRUCTION 0
- CFI_INSTRUCTION 0
- CFI_INSTRUCTION 0
- CFI_INSTRUCTION 0
- CFI_INSTRUCTION 0
- CFI_INSTRUCTION 0
- CFI_INSTRUCTION 0
- CFI_INSTRUCTION 0
- CFI_INSTRUCTION 0
- CFI_INSTRUCTION 0
- CFI_INSTRUCTION 0
- CFI_INSTRUCTION 0
- CFI_INSTRUCTION 0
- CFI_INSTRUCTION 0
- CFI_INSTRUCTION 0
- CFI_INSTRUCTION 0
- STRWui killed %w1, killed %x0, 1 :: (store 4 into %ir.dst1)
- RET %lr
-
-...
-# CHECK-LABEL: name: store-pair
-# CHECK: STPWi
Added: llvm/trunk/test/CodeGen/AArch64/ldst-opt.mir
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AArch64/ldst-opt.mir?rev=292625&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/AArch64/ldst-opt.mir (added)
+++ llvm/trunk/test/CodeGen/AArch64/ldst-opt.mir Fri Jan 20 12:04:27 2017
@@ -0,0 +1,132 @@
+# RUN: llc -mtriple=aarch64--linux-gnu -run-pass=aarch64-ldst-opt %s -verify-machineinstrs -o - 2>&1 | FileCheck %s
+--- |
+ define void @promote-load-from-store() { ret void }
+ define void @store-pair() { ret void }
+ define void @store-pair-clearkill0() { ret void }
+ define void @store-pair-clearkill1() { ret void }
+...
+---
+name: promote-load-from-store
+tracksRegLiveness: true
+body: |
+ bb.0:
+ liveins: %w1, %x0, %lr
+
+ STRWui killed %w1, %x0, 0 :: (store 4)
+ CFI_INSTRUCTION 0
+ CFI_INSTRUCTION 0
+ CFI_INSTRUCTION 0
+ CFI_INSTRUCTION 0
+ CFI_INSTRUCTION 0
+ CFI_INSTRUCTION 0
+ CFI_INSTRUCTION 0
+ CFI_INSTRUCTION 0
+ CFI_INSTRUCTION 0
+ CFI_INSTRUCTION 0
+ CFI_INSTRUCTION 0
+ CFI_INSTRUCTION 0
+ CFI_INSTRUCTION 0
+ CFI_INSTRUCTION 0
+ CFI_INSTRUCTION 0
+ CFI_INSTRUCTION 0
+ CFI_INSTRUCTION 0
+ CFI_INSTRUCTION 0
+ CFI_INSTRUCTION 0
+ CFI_INSTRUCTION 0
+ %w0 = LDRHHui killed %x0, 1 :: (load 2)
+ RET %lr, implicit %w0
+
+...
+# Don't count transient instructions towards search limits.
+# CHECK-LABEL: name: promote-load-from-store
+# CHECK: STRWui %w1
+# CHECK: UBFMWri %w1
+---
+name: store-pair
+tracksRegLiveness: true
+body: |
+ bb.0:
+ liveins: %w1, %x0, %lr
+
+ STRWui %w1, %x0, 0 :: (store 4)
+ CFI_INSTRUCTION 0
+ CFI_INSTRUCTION 0
+ CFI_INSTRUCTION 0
+ CFI_INSTRUCTION 0
+ CFI_INSTRUCTION 0
+ CFI_INSTRUCTION 0
+ CFI_INSTRUCTION 0
+ CFI_INSTRUCTION 0
+ CFI_INSTRUCTION 0
+ CFI_INSTRUCTION 0
+ CFI_INSTRUCTION 0
+ CFI_INSTRUCTION 0
+ CFI_INSTRUCTION 0
+ CFI_INSTRUCTION 0
+ CFI_INSTRUCTION 0
+ CFI_INSTRUCTION 0
+ CFI_INSTRUCTION 0
+ CFI_INSTRUCTION 0
+ CFI_INSTRUCTION 0
+ CFI_INSTRUCTION 0
+ STRWui killed %w1, killed %x0, 1 :: (store 4)
+ RET %lr
+
+...
+# CHECK-LABEL: name: store-pair
+# CHECK: STPWi
+---
+name: store-pair-clearkill0
+tracksRegLiveness: true
+body: |
+ bb.0:
+ liveins: %w1, %x0, %lr
+
+ STRWui %w1, %x0, 0 :: (store 4)
+ %w2 = COPY %w1
+ %x3 = COPY %x0
+ STRWui killed %w1, killed %x0, 1 :: (store 4)
+ RET %lr
+...
+# When merging a lower store with an upper one, we must clear kill flags on
+# the lower store.
+# CHECK-LABEL: store-pair-clearkill0
+# CHECK-NOT: STPWi %w1, killed %w1, %x0, 0 :: (store 4)
+# CHECK: STPWi %w1, %w1, %x0, 0 :: (store 4)
+# CHECK: %w2 = COPY %w1
+# CHECK: RET %lr
+---
+name: store-pair-clearkill1
+tracksRegLiveness: true
+body: |
+ bb.0:
+ liveins: %x0, %lr
+
+ %w1 = MOVi32imm 13
+ %w2 = MOVi32imm 7
+ STRWui %w1, %x0, 1 :: (store 4)
+ %w2 = COPY killed %w1
+ STRWui killed %w2, %x0, 0 :: (store 4)
+
+ %w1 = MOVi32imm 42
+ %w2 = MOVi32imm 7
+ STRWui %w1, %x0, 0 :: (store 4)
+ %w2 = COPY killed %w1
+ STRWui killed %w2, killed %x0, 1 :: (store 4)
+
+ RET %lr
+...
+# When merging an upper store with a lower one, kill flags along the way need
+# to be removed; In this case the kill flag on %w1.
+# CHECK-LABEL: store-pair-clearkill1
+# CHECK: %w1 = MOVi32imm
+# CHECK: %w2 = MOVi32imm
+# CHECK-NOT: %w2 = COPY killed %w1
+# CHECK: %w2 = COPY %w1
+# CHECK: STPWi killed %w2, %w1, %x0, 0
+
+# CHECK: %w1 = MOVi32imm
+# CHECK: %w2 = MOVi32imm
+# CHECK-NOT: %w2 = COPY killed %w1
+# CHECK: %w2 = COPY %w1
+# CHECK: STPWi %w1, killed %w2, killed %x0, 0
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