Revert "[AArch64] Verify ldp/stp alignment stricter"

[fmayer]

Reverts #83948

This broke the ASan buildbot: https://lab.llvm.org/buildbot/#/builders/168/builds/19054/steps/10/logs/stdio

[llvmbot]

@llvm/pr-subscribers-backend-aarch64

Author: Florian Mayer (fmayer)

Changes

Reverts llvm/llvm-project#83948

This broke the ASan buildbot: https://lab.llvm.org/buildbot/#/builders/168/builds/19054/steps/10/logs/stdio

---

Full diff: https://github.com/llvm/llvm-project/pull/84096.diff

2 Files Affected:

• (modified) llvm/lib/Target/AArch64/AArch64LoadStoreOptimizer.cpp (+19-25)
• (removed) llvm/test/CodeGen/AArch64/ldp-stp-unknown-size.mir (-56)

diff --git a/llvm/lib/Target/AArch64/AArch64LoadStoreOptimizer.cpp b/llvm/lib/Target/AArch64/AArch64LoadStoreOptimizer.cpp
index abfb1f43a9c81a..926a89466255ca 100644
--- a/llvm/lib/Target/AArch64/AArch64LoadStoreOptimizer.cpp
+++ b/llvm/lib/Target/AArch64/AArch64LoadStoreOptimizer.cpp
@@ -62,8 +62,6 @@ STATISTIC(NumUnscaledPairCreated,
           "Number of load/store from unscaled generated");
 STATISTIC(NumZeroStoresPromoted, "Number of narrow zero stores promoted");
 STATISTIC(NumLoadsFromStoresPromoted, "Number of loads from stores promoted");
-STATISTIC(NumFailedAlignmentCheck, "Number of load/store pair transformation "
-                                   "not passed the alignment check");
 
 DEBUG_COUNTER(RegRenamingCounter, DEBUG_TYPE "-reg-renaming",
               "Controls which pairs are considered for renaming");
@@ -2339,6 +2337,9 @@ bool AArch64LoadStoreOpt::tryToPairLdStInst(MachineBasicBlock::iterator &MBBI) {
   MachineBasicBlock::iterator Paired =
       findMatchingInsn(MBBI, Flags, LdStLimit, /* FindNarrowMerge = */ false);
   if (Paired != E) {
+    ++NumPairCreated;
+    if (TII->hasUnscaledLdStOffset(MI))
+      ++NumUnscaledPairCreated;
     // Keeping the iterator straight is a pain, so we let the merge routine tell
     // us what the next instruction is after it's done mucking about.
     auto Prev = std::prev(MBBI);
@@ -2348,27 +2349,24 @@ bool AArch64LoadStoreOpt::tryToPairLdStInst(MachineBasicBlock::iterator &MBBI) {
     MachineMemOperand *MemOp =
         MI.memoperands_empty() ? nullptr : MI.memoperands().front();
 
-    // If a load/store arrives and ldp/stp-aligned-only feature is opted, check
-    // that the alignment of the source pointer is at least double the alignment
-    // of the type.
-    if ((MI.mayLoad() && Subtarget->hasLdpAlignedOnly()) ||
-        (MI.mayStore() && Subtarget->hasStpAlignedOnly())) {
-      // If there is no size/align information, cancel the transformation.
-      if (!MemOp || !MemOp->getMemoryType().isValid()) {
-        NumFailedAlignmentCheck++;
-        return false;
-      }
+    // Get the needed alignments to check them if
+    // ldp-aligned-only/stp-aligned-only features are opted.
+    uint64_t MemAlignment = MemOp ? MemOp->getAlign().value() : -1;
+    uint64_t TypeAlignment = MemOp ? Align(MemOp->getSize()).value() : -1;
 
-      // Get the needed alignments to check them if
-      // ldp-aligned-only/stp-aligned-only features are opted.
-      uint64_t MemAlignment = MemOp->getAlign().value();
-      uint64_t TypeAlignment = Align(MemOp->getSize()).value();
+    // If a load arrives and ldp-aligned-only feature is opted, check that the
+    // alignment of the source pointer is at least double the alignment of the
+    // type.
+    if (MI.mayLoad() && Subtarget->hasLdpAlignedOnly() && MemOp &&
+        MemAlignment < 2 * TypeAlignment)
+      return false;
 
-      if (MemAlignment < 2 * TypeAlignment) {
-        NumFailedAlignmentCheck++;
-        return false;
-      }
-    }
+    // If a store arrives and stp-aligned-only feature is opted, check that the
+    // alignment of the source pointer is at least double the alignment of the
+    // type.
+    if (MI.mayStore() && Subtarget->hasStpAlignedOnly() && MemOp &&
+        MemAlignment < 2 * TypeAlignment)
+      return false;
 
     MBBI = mergePairedInsns(MBBI, Paired, Flags);
     // Collect liveness info for instructions between Prev and the new position
@@ -2376,10 +2374,6 @@ bool AArch64LoadStoreOpt::tryToPairLdStInst(MachineBasicBlock::iterator &MBBI) {
     for (auto I = std::next(Prev); I != MBBI; I++)
       updateDefinedRegisters(*I, DefinedInBB, TRI);
 
-    ++NumPairCreated;
-    if (TII->hasUnscaledLdStOffset(MI))
-      ++NumUnscaledPairCreated;
-
     return true;
   }
   return false;
diff --git a/llvm/test/CodeGen/AArch64/ldp-stp-unknown-size.mir b/llvm/test/CodeGen/AArch64/ldp-stp-unknown-size.mir
deleted file mode 100644
index 3234a7dc11f05d..00000000000000
--- a/llvm/test/CodeGen/AArch64/ldp-stp-unknown-size.mir
+++ /dev/null
@@ -1,56 +0,0 @@
-# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py UTC_ARGS: --version 4
-# RUN: llc -O2 -mtriple=aarch64 -mcpu=ampere1 -simplify-mir -o - %s -run-pass=aarch64-ldst-opt | FileCheck %s --check-prefixes=CHECK
-# RUN: llc -O2 -mtriple=aarch64 -simplify-mir -o - %s -run-pass=aarch64-ldst-opt | FileCheck %s --check-prefixes=CHECK-DEFAULT
-
---- |
-  define i32 @ldp_no_size_info(ptr %0) #0 {
-    %2 = ptrtoint ptr %0 to i64
-    %3 = and i64 %2, -64
-    %4 = inttoptr i64 %3 to ptr
-    %5 = load i32, ptr %4, align 4
-    %6 = getelementptr inbounds i32, ptr %4, i64 1
-    %7 = load i32, ptr %6, align 4
-    %8 = add nsw i32 %7, %5
-    ret i32 %8
-  }
-
-...
----
-name:            ldp_no_size_info
-alignment:       64
-tracksRegLiveness: true
-tracksDebugUserValues: true
-liveins:
-  - { reg: '$x0' }
-frameInfo:
-  maxAlignment:    1
-  maxCallFrameSize: 0
-machineFunctionInfo:
-  hasRedZone:      false
-body:             |
-  bb.0 (%ir-block.1):
-    liveins: $x0
-
-    ; CHECK-LABEL: name: ldp_no_size_info
-    ; CHECK: liveins: $x0
-    ; CHECK-NEXT: {{  $}}
-    ; CHECK-NEXT: renamable $x8 = ANDXri killed renamable $x0, 7865
-    ; CHECK-NEXT: renamable $w9 = LDRWui renamable $x8, 0 :: (load unknown-size from %ir.4, align 1)
-    ; CHECK-NEXT: renamable $w8 = LDRWui killed renamable $x8, 1 :: (load unknown-size from %ir.6, align 1)
-    ; CHECK-NEXT: $w0 = ADDWrs killed renamable $w8, killed renamable $w9, 0
-    ; CHECK-NEXT: RET undef $lr, implicit $w0
-    ;
-    ; CHECK-DEFAULT-LABEL: name: ldp_no_size_info
-    ; CHECK-DEFAULT: liveins: $x0
-    ; CHECK-DEFAULT-NEXT: {{  $}}
-    ; CHECK-DEFAULT-NEXT: renamable $x8 = ANDXri killed renamable $x0, 7865
-    ; CHECK-DEFAULT-NEXT: renamable $w9, renamable $w8 = LDPWi renamable $x8, 0 :: (load unknown-size from %ir.4, align 1), (load unknown-size from %ir.6, align 1)
-    ; CHECK-DEFAULT-NEXT: $w0 = ADDWrs killed renamable $w8, killed renamable $w9, 0
-    ; CHECK-DEFAULT-NEXT: RET undef $lr, implicit $w0
-    renamable $x8 = ANDXri killed renamable $x0, 7865
-    renamable $w9 = LDRWui renamable $x8, 0 :: (load unknown-size from %ir.4)
-    renamable $w8 = LDRWui killed renamable $x8, 1 :: (load unknown-size from %ir.6)
-    $w0 = ADDWrs killed renamable $w8, killed renamable $w9, 0
-    RET undef $lr, implicit $w0
-
-...