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

llvm-svn: 292625

2 files changed, 132 insertions, 133 deletions

diff --git a/llvm/test/CodeGen/AArch64/ldst-opt-dbg-limit.mir b/llvm/test/CodeGen/AArch64/ldst-opt-dbg-limit.mir
deleted file mode 100644
index 45542cae98f..00000000000
--- a/llvm/test/CodeGen/AArch64/ldst-opt-dbg-limit.mir
+++ /dev/null
@@ -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
diff --git a/llvm/test/CodeGen/AArch64/ldst-opt.mir b/llvm/test/CodeGen/AArch64/ldst-opt.mir
new file mode 100644
index 00000000000..8f0b71be348
--- /dev/null
+++ b/llvm/test/CodeGen/AArch64/ldst-opt.mir
@@ -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