[llvm] a099c91 - [LAA] Add tests for using inbounds flags only used in predicated blocks.

[Florian Hahn via llvm-commits]

Author: Florian Hahn
Date: 2025-09-30T22:06:17+01:00
New Revision: a099c91eb8e275c385859f7b3ddee3f0b08db558

URL: https://github.com/llvm/llvm-project/commit/a099c91eb8e275c385859f7b3ddee3f0b08db558
DIFF: https://github.com/llvm/llvm-project/commit/a099c91eb8e275c385859f7b3ddee3f0b08db558.diff

LOG: [LAA] Add tests for using inbounds flags only used in predicated blocks.

Test for https://github.com/llvm/llvm-project/issues/160912.

Added: 
    llvm/test/Analysis/LoopAccessAnalysis/inbounds-gep-in-predicated-blocks.ll

Modified: 
    

Removed: 
    


################################################################################
diff  --git a/llvm/test/Analysis/LoopAccessAnalysis/inbounds-gep-in-predicated-blocks.ll b/llvm/test/Analysis/LoopAccessAnalysis/inbounds-gep-in-predicated-blocks.ll
new file mode 100644
index 0000000000000..6eed0ec864820
--- /dev/null
+++ b/llvm/test/Analysis/LoopAccessAnalysis/inbounds-gep-in-predicated-blocks.ll
@@ -0,0 +1,98 @@
+; NOTE: Assertions have been autogenerated by utils/update_analyze_test_checks.py UTC_ARGS: --version 6
+; RUN: opt -passes='print<access-info>' -disable-output %s 2>&1 | FileCheck %s
+
+; unsigned long long s0 = 0, s1 = 0;
+; for (int i = 0; i < 100; i++) {
+;   if (i % 4 == 0) {
+;     A[s0] = 2;  // A[0], A[4], A[8], A[12], ...
+;     A[s1] = 1;  // A[0], A[8], A[16], A[24], ...
+;   }
+;   s0 += (1ULL << 62) + 1;
+;   s1 += (1ULL << 62) + 2;
+; }
+; FIXME: We cannot use inbounds on idx.0, idx.1 to infer no-wrap (and determine
+; there are no dependences), as the pointers are not dereferenced in all loop iterations.
+define void @test_inbounds_gep_used_in_predicated_block(ptr %A, i64 %n) {
+; CHECK-LABEL: 'test_inbounds_gep_used_in_predicated_block'
+; CHECK-NEXT:    loop.header:
+; CHECK-NEXT:      Memory dependences are safe
+; CHECK-NEXT:      Dependences:
+; CHECK-NEXT:      Run-time memory checks:
+; CHECK-NEXT:      Grouped accesses:
+; CHECK-EMPTY:
+; CHECK-NEXT:      Non vectorizable stores to invariant address were not found in loop.
+; CHECK-NEXT:      SCEV assumptions:
+; CHECK-EMPTY:
+; CHECK-NEXT:      Expressions re-written:
+;
+entry:
+  br label %loop.header
+
+loop.header:
+  %i = phi i64 [ 0, %entry ], [ %i.next, %loop.latch ]
+  %offset.0 = phi i64 [ 0, %entry ], [ %offset.0.next, %loop.latch ]
+  %offset.1 = phi i64 [ 0, %entry ], [ %offset.1.next, %loop.latch ]
+  %idx.0 = getelementptr inbounds i8, ptr %A, i64 %offset.0
+  %idx.1 = getelementptr inbounds i8, ptr %A, i64 %offset.1
+  %mask = and i64 %i, 3
+  %cond = icmp eq i64 %mask, 0
+  br i1 %cond, label %if.then, label %loop.latch
+
+if.then:
+  store i8 2, ptr %idx.0
+  store i8 1, ptr %idx.1
+  br label %loop.latch
+
+loop.latch:
+  %i.next = add nuw nsw i64 %i, 1
+  %offset.0.next = add i64 %offset.0, 4611686018427387905 ; 2^62 + 1
+  %offset.1.next = add i64 %offset.1, 4611686018427387906 ; 2^62 + 2
+  %cond.exit = icmp eq i64 %i.next, 100
+  br i1 %cond.exit, label %exit, label %loop.header
+
+exit:
+  ret void
+}
+
+define void @test_header_existing(ptr %src, ptr %dst, i64 %start) {
+; CHECK-LABEL: 'test_header_existing'
+; CHECK-NEXT:    loop.header:
+; CHECK-NEXT:      Memory dependences are safe with run-time checks
+; CHECK-NEXT:      Dependences:
+; CHECK-NEXT:      Run-time memory checks:
+; CHECK-NEXT:      Check 0:
+; CHECK-NEXT:        Comparing group GRP0:
+; CHECK-NEXT:        ptr %dst
+; CHECK-NEXT:        Against group GRP1:
+; CHECK-NEXT:          %gep.src = getelementptr nusw { i8, i8, i32 }, ptr %src, i64 %iv.next
+; CHECK-NEXT:      Grouped accesses:
+; CHECK-NEXT:        Group GRP0:
+; CHECK-NEXT:          (Low: %dst High: (1 + %dst))
+; CHECK-NEXT:            Member: %dst
+; CHECK-NEXT:        Group GRP1:
+; CHECK-NEXT:          (Low: (8 + (8 * %start) + %src) High: (809 + %src))
+; CHECK-NEXT:            Member: {(8 + (8 * %start) + %src),+,8}<%loop.header>
+; CHECK-EMPTY:
+; CHECK-NEXT:      Non vectorizable stores to invariant address were not found in loop.
+; CHECK-NEXT:      SCEV assumptions:
+; CHECK-EMPTY:
+; CHECK-NEXT:      Expressions re-written:
+;
+entry:
+  br label %loop.header
+
+loop.header:
+  %iv = phi i64 [ %start, %entry ], [ %iv.next, %loop.latch ]
+  %ec = icmp eq i64 %iv, 100
+  br i1 %ec, label %exit, label %loop.latch
+
+loop.latch:
+  %iv.next = add i64 %iv, 1
+  %gep.src = getelementptr nusw { i8, i8, i32 }, ptr %src, i64 %iv.next
+  %l = load i8, ptr %gep.src, align 1
+  store i8 %l, ptr %dst, align 1
+  br label %loop.header
+
+exit:
+  ret void
+}