[llvm] 86f655c - [LAA] Add tests showing unnecessary RT check due to applying loop guards

Florian Hahn via llvm-commits llvm-commits at lists.llvm.org
Tue May 14 10:28:07 PDT 2024


Author: Florian Hahn
Date: 2024-05-14T18:27:37+01:00
New Revision: 86f655cb4e2f4134d48219a2959a10c90e3396cb

URL: https://github.com/llvm/llvm-project/commit/86f655cb4e2f4134d48219a2959a10c90e3396cb
DIFF: https://github.com/llvm/llvm-project/commit/86f655cb4e2f4134d48219a2959a10c90e3396cb.diff

LOG: [LAA] Add tests showing unnecessary RT check due to applying loop guards

Test courtesy to @bjope showing a regression due to
ecae3ed958481cba7d60868cf3504292f7f4fdf5.

Added: 
    llvm/test/Analysis/LoopAccessAnalysis/is-safe-dep-distance-with-loop-guards.ll

Modified: 
    

Removed: 
    


################################################################################
diff  --git a/llvm/test/Analysis/LoopAccessAnalysis/is-safe-dep-distance-with-loop-guards.ll b/llvm/test/Analysis/LoopAccessAnalysis/is-safe-dep-distance-with-loop-guards.ll
new file mode 100644
index 0000000000000..bfa735df064d5
--- /dev/null
+++ b/llvm/test/Analysis/LoopAccessAnalysis/is-safe-dep-distance-with-loop-guards.ll
@@ -0,0 +1,140 @@
+; NOTE: Assertions have been autogenerated by utils/update_analyze_test_checks.py UTC_ARGS: --version 4
+; RUN: opt -passes='print<access-info>' -disable-output %s 2>&1 | FileCheck %s
+
+target datalayout = "S16-p:16:16-i1:16-i8:8-i32:16-i64:16-i128:16"
+
+define void @safe_deps_1_due_to_dependence_distance(i16  %n, ptr %p) {
+; CHECK-LABEL: 'safe_deps_1_due_to_dependence_distance'
+; CHECK-NEXT:    loop:
+; 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 ([[GRP1:0x[0-9a-f]+]]):
+; CHECK-NEXT:          %gep.iv = getelementptr inbounds i32, ptr %p, i16 %iv
+; CHECK-NEXT:        Against group ([[GRP2:0x[0-9a-f]+]]):
+; CHECK-NEXT:          %gep.off.iv = getelementptr i32, ptr %gep.off, i16 %iv
+; CHECK-NEXT:      Grouped accesses:
+; CHECK-NEXT:        Group [[GRP1]]:
+; CHECK-NEXT:          (Low: %p High: ((4 * %n) + %p))
+; CHECK-NEXT:            Member: {%p,+,4}<nuw><%loop>
+; CHECK-NEXT:        Group [[GRP2]]:
+; CHECK-NEXT:          (Low: ((4 * %n) + %p) High: ((8 * %n) + %p))
+; CHECK-NEXT:            Member: {((4 * %n) + %p),+,4}<nw><%loop>
+; 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:
+  %cmp42 = icmp sgt i16 %n, 0
+  br i1 %cmp42, label %ph, label %exit
+
+ph:
+  %gep.off = getelementptr i32, ptr %p, i16 %n
+  br label %loop
+
+loop:
+  %iv = phi i16 [ 0, %ph ], [ %iv.next, %loop ]
+  %gep.iv = getelementptr inbounds i32, ptr %p, i16 %iv
+  store i32 0, ptr %gep.iv, align 1
+  %gep.off.iv = getelementptr i32, ptr %gep.off, i16 %iv
+  store i32 1, ptr %gep.off.iv, align 1
+  %iv.next = add i16 %iv, 1
+  %exitcond.not = icmp eq i16 %iv.next, %n
+  br i1 %exitcond.not, label %exit, label %loop
+
+exit:
+  ret void
+}
+
+define void @safe_deps_2_due_to_dependence_distance(i16 %n, ptr %p3, i16 noundef %q, ptr %p1, ptr %p2) {
+; CHECK-LABEL: 'safe_deps_2_due_to_dependence_distance'
+; CHECK-NEXT:    loop:
+; 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 ([[GRP3:0x[0-9a-f]+]]):
+; CHECK-NEXT:          %arrayidx22 = getelementptr inbounds [2 x i32], ptr %alloca, i16 %iv
+; CHECK-NEXT:        Against group ([[GRP4:0x[0-9a-f]+]]):
+; CHECK-NEXT:          %arrayidx33 = getelementptr inbounds i8, ptr %arrayidx22, i16 4
+; CHECK-NEXT:      Check 1:
+; CHECK-NEXT:        Comparing group ([[GRP3]]):
+; CHECK-NEXT:          %arrayidx22 = getelementptr inbounds [2 x i32], ptr %alloca, i16 %iv
+; CHECK-NEXT:        Against group ([[GRP5:0x[0-9a-f]+]]):
+; CHECK-NEXT:          %arrayidx42 = getelementptr inbounds [2 x i32], ptr %arrayidx40, i16 %iv
+; CHECK-NEXT:      Check 2:
+; CHECK-NEXT:        Comparing group ([[GRP3]]):
+; CHECK-NEXT:          %arrayidx22 = getelementptr inbounds [2 x i32], ptr %alloca, i16 %iv
+; CHECK-NEXT:        Against group ([[GRP6:0x[0-9a-f]+]]):
+; CHECK-NEXT:          %arrayidx53 = getelementptr inbounds i8, ptr %arrayidx42, i16 4
+; CHECK-NEXT:      Check 3:
+; CHECK-NEXT:        Comparing group ([[GRP4]]):
+; CHECK-NEXT:          %arrayidx33 = getelementptr inbounds i8, ptr %arrayidx22, i16 4
+; CHECK-NEXT:        Against group ([[GRP5]]):
+; CHECK-NEXT:          %arrayidx42 = getelementptr inbounds [2 x i32], ptr %arrayidx40, i16 %iv
+; CHECK-NEXT:      Check 4:
+; CHECK-NEXT:        Comparing group ([[GRP4]]):
+; CHECK-NEXT:          %arrayidx33 = getelementptr inbounds i8, ptr %arrayidx22, i16 4
+; CHECK-NEXT:        Against group ([[GRP6]]):
+; CHECK-NEXT:          %arrayidx53 = getelementptr inbounds i8, ptr %arrayidx42, i16 4
+; CHECK-NEXT:      Check 5:
+; CHECK-NEXT:        Comparing group ([[GRP5]]):
+; CHECK-NEXT:          %arrayidx42 = getelementptr inbounds [2 x i32], ptr %arrayidx40, i16 %iv
+; CHECK-NEXT:        Against group ([[GRP6]]):
+; CHECK-NEXT:          %arrayidx53 = getelementptr inbounds i8, ptr %arrayidx42, i16 4
+; CHECK-NEXT:      Grouped accesses:
+; CHECK-NEXT:        Group [[GRP3]]:
+; CHECK-NEXT:          (Low: %alloca High: (-4 + (8 * %n) + %alloca))
+; CHECK-NEXT:            Member: {%alloca,+,8}<nuw><%loop>
+; CHECK-NEXT:        Group [[GRP4]]:
+; CHECK-NEXT:          (Low: (4 + %alloca) High: ((8 * %n) + %alloca))
+; CHECK-NEXT:            Member: {(4 + %alloca),+,8}<nuw><%loop>
+; CHECK-NEXT:        Group [[GRP5]]:
+; CHECK-NEXT:          (Low: ((8 * %n) + %alloca) High: (-4 + (16 * %n) + %alloca))
+; CHECK-NEXT:            Member: {((8 * %n) + %alloca),+,8}<nw><%loop>
+; CHECK-NEXT:        Group [[GRP6]]:
+; CHECK-NEXT:          (Low: (4 + (8 * %n) + %alloca) High: ((16 * %n) + %alloca))
+; CHECK-NEXT:            Member: {(4 + (8 * %n) + %alloca),+,8}<nw><%loop>
+; CHECK-EMPTY:
+; CHECK-NEXT:      Non vectorizable stores to invariant address were not found in loop.
+; CHECK-NEXT:      SCEV assumptions:
+; CHECK-NEXT:      {((8 * %n) + %alloca),+,8}<nw><%loop> Added Flags: <nusw>
+; CHECK-NEXT:      {(4 + (8 * %n) + %alloca),+,8}<nw><%loop> Added Flags: <nusw>
+; CHECK-EMPTY:
+; CHECK-NEXT:      Expressions re-written:
+;
+entry:
+  %0 = shl i16 %n, 1
+  %alloca = alloca [2 x i32], i16 %0
+  %arrayidx1 = getelementptr inbounds i32, ptr %p1, i16 %q
+  %arrayidx2 = getelementptr inbounds i8, ptr %p3, i16 2
+  %arrayidx4 = getelementptr inbounds i32, ptr %p2, i16 %q
+  %cmp42 = icmp sgt i16 %n, 0
+  br i1 %cmp42, label %ph, label %exit
+
+ph:
+  %arrayidx40 = getelementptr inbounds [2 x i32], ptr %alloca, i16 %n
+  br label %loop
+
+loop:
+  %iv = phi i16 [ 0, %ph ], [ %iv.next, %loop ]
+  %arrayidx6 = getelementptr inbounds i32, ptr %arrayidx1, i16 %iv
+  %arrayidx11 = getelementptr inbounds i32, ptr %arrayidx4, i16 %iv
+  %arrayidx22 = getelementptr inbounds [2 x i32], ptr %alloca, i16 %iv
+  store i32 10, ptr %arrayidx22
+  %arrayidx33 = getelementptr inbounds i8, ptr %arrayidx22, i16 4
+  store i32 16, ptr %arrayidx33
+  %arrayidx42 = getelementptr inbounds [2 x i32], ptr %arrayidx40, i16 %iv
+  store i32 19, ptr %arrayidx42
+  %arrayidx53 = getelementptr inbounds i8, ptr %arrayidx42, i16 4
+  store i32 23, ptr %arrayidx53
+  %iv.next = add nuw nsw i16 %iv, 1
+  %exitcond.not = icmp eq i16 %iv.next, %n
+  br i1 %exitcond.not, label %exit, label %loop
+
+exit:
+  ret void
+}


        


More information about the llvm-commits mailing list