[llvm] [Loads] Pass DominatorTree if available (PR #95752)

[via llvm-commits]

https://github.com/ruiling updated https://github.com/llvm/llvm-project/pull/95752

>From 841fb4a476bdef4fe59fadef8447b598410947a9 Mon Sep 17 00:00:00 2001
From: Ruiling Song <ruiling.song at amd.com>
Date: Mon, 17 Jun 2024 15:36:06 +0800
Subject: [PATCH] [Loads] Pass DominatorTree if available

For better dominance check inside the function.
---
 llvm/lib/Analysis/Loads.cpp                   |  2 +-
 .../LICM/hoist-speculatable-load.ll           | 63 +++++++++++++++++++
 2 files changed, 64 insertions(+), 1 deletion(-)
 create mode 100644 llvm/test/Transforms/LICM/hoist-speculatable-load.ll

diff --git a/llvm/lib/Analysis/Loads.cpp b/llvm/lib/Analysis/Loads.cpp
index 478302d687b53..2b8197066e8e9 100644
--- a/llvm/lib/Analysis/Loads.cpp
+++ b/llvm/lib/Analysis/Loads.cpp
@@ -165,7 +165,7 @@ static bool isDereferenceableAndAlignedPointer(
     if (getKnowledgeForValue(
             V, {Attribute::Dereferenceable, Attribute::Alignment}, AC,
             [&](RetainedKnowledge RK, Instruction *Assume, auto) {
-              if (!isValidAssumeForContext(Assume, CtxI))
+              if (!isValidAssumeForContext(Assume, CtxI, DT))
                 return false;
               if (RK.AttrKind == Attribute::Alignment)
                 AlignRK = std::max(AlignRK, RK);
diff --git a/llvm/test/Transforms/LICM/hoist-speculatable-load.ll b/llvm/test/Transforms/LICM/hoist-speculatable-load.ll
new file mode 100644
index 0000000000000..307a93b40ca8b
--- /dev/null
+++ b/llvm/test/Transforms/LICM/hoist-speculatable-load.ll
@@ -0,0 +1,63 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -passes=licm -S < %s | FileCheck %s
+
+define dso_local void @f(i32 %ptr_i, ptr %ptr2, i32 %n, i32 %n2) {
+; CHECK-LABEL: @f(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[CMP7:%.*]] = icmp slt i32 0, [[N:%.*]]
+; CHECK-NEXT:    [[PTR:%.*]] = inttoptr i32 [[PTR_I:%.*]] to ptr
+; CHECK-NEXT:    call void @llvm.assume(i1 true) [ "align"(ptr [[PTR]], i32 16), "dereferenceable"(ptr [[PTR]], i32 16) ]
+; CHECK-NEXT:    br i1 [[CMP7]], label [[FOR_BODY_LR_PH:%.*]], label [[IF0:%.*]]
+; CHECK:       if0:
+; CHECK-NEXT:    store i32 0, ptr [[PTR2:%.*]], align 4
+; CHECK-NEXT:    br label [[FOR_BODY_LR_PH]]
+; CHECK:       for.body.lr.ph:
+; CHECK-NEXT:    [[TOBOOL_NOT:%.*]] = icmp eq i32 [[N2:%.*]], 0
+; CHECK-NEXT:    [[TMP0:%.*]] = load i32, ptr [[PTR]], align 4
+; CHECK-NEXT:    br label [[FOR_BODY:%.*]]
+; CHECK:       for.body:
+; CHECK-NEXT:    [[I_08:%.*]] = phi i32 [ 0, [[FOR_BODY_LR_PH]] ], [ [[INC:%.*]], [[IF_END:%.*]] ]
+; CHECK-NEXT:    br i1 [[TOBOOL_NOT]], label [[IF_END]], label [[IF:%.*]]
+; CHECK:       if:
+; CHECK-NEXT:    store i32 [[TMP0]], ptr [[PTR2]], align 4
+; CHECK-NEXT:    br label [[IF_END]]
+; CHECK:       if.end:
+; CHECK-NEXT:    [[INC]] = add nuw nsw i32 [[I_08]], 1
+; CHECK-NEXT:    [[CMP:%.*]] = icmp slt i32 [[INC]], [[N]]
+; CHECK-NEXT:    br i1 [[CMP]], label [[FOR_BODY]], label [[EXIT:%.*]]
+; CHECK:       exit:
+; CHECK-NEXT:    ret void
+;
+entry:
+  %cmp7 = icmp slt i32 0, %n
+  %ptr = inttoptr i32 %ptr_i to ptr
+  call void @llvm.assume(i1 true) [ "align"(ptr %ptr, i32 16), "dereferenceable"(ptr %ptr, i32 16) ]
+  br i1 %cmp7, label %for.body.lr.ph, label %if0
+
+if0:
+  store i32 0, ptr %ptr2, align 4
+  br label %for.body.lr.ph
+
+for.body.lr.ph:                                   ; preds = %entry
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.lr.ph, %if.end
+  %i.08 = phi i32 [ 0, %for.body.lr.ph ], [ %inc, %if.end ]
+  %tobool.not = icmp eq i32 %n2, 0
+  br i1 %tobool.not, label %if.end, label %if
+
+if:
+  %0 = load i32, ptr %ptr, align 4, !invariant.load !{}
+  store i32 %0, ptr %ptr2, align 4
+  br label %if.end
+
+if.end:                                           ; preds = %for.body
+  %inc = add nuw nsw i32 %i.08, 1
+  %cmp = icmp slt i32 %inc, %n
+  br i1 %cmp, label %for.body, label %exit
+
+exit:                                         ; preds = %if.end, %entry
+  ret void
+}
+
+declare void @llvm.assume(i1 noundef)