[llvm] 50b45b2 - [LAA] Add tests with forward dependences known via assumes.

Florian Hahn via llvm-commits llvm-commits at lists.llvm.org
Wed May 8 07:46:00 PDT 2024


Author: Florian Hahn
Date: 2024-05-08T15:45:38+01:00
New Revision: 50b45b24220ead33cf5cedc49c13e0336297e4eb

URL: https://github.com/llvm/llvm-project/commit/50b45b24220ead33cf5cedc49c13e0336297e4eb
DIFF: https://github.com/llvm/llvm-project/commit/50b45b24220ead33cf5cedc49c13e0336297e4eb.diff

LOG: [LAA] Add tests with forward dependences known via assumes.

Added: 
    llvm/test/Analysis/LoopAccessAnalysis/offset-range-known-via-assume.ll

Modified: 
    

Removed: 
    


################################################################################
diff  --git a/llvm/test/Analysis/LoopAccessAnalysis/offset-range-known-via-assume.ll b/llvm/test/Analysis/LoopAccessAnalysis/offset-range-known-via-assume.ll
new file mode 100644
index 0000000000000..7e36da78d6aaa
--- /dev/null
+++ b/llvm/test/Analysis/LoopAccessAnalysis/offset-range-known-via-assume.ll
@@ -0,0 +1,244 @@
+; 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 = "e-m:o-i64:64-i128:128-n32:64-S128"
+
+declare void @llvm.assume(i1)
+
+declare void @use(ptr noundef)
+
+; TODO: %offset is known positive via assume, so we should be able to detect the
+; forward dependence.
+define void @offset_i8_known_positive_via_assume_forward_dep_1(ptr %A, i64 %offset, i64 %N) {
+; CHECK-LABEL: 'offset_i8_known_positive_via_assume_forward_dep_1'
+; 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 = getelementptr inbounds i8, ptr %A, i64 %iv
+; CHECK-NEXT:        Against group ([[GRP2:0x[0-9a-f]+]]):
+; CHECK-NEXT:          %gep.off = getelementptr inbounds i8, ptr %off, i64 %iv
+; CHECK-NEXT:      Grouped accesses:
+; CHECK-NEXT:        Group [[GRP1]]:
+; CHECK-NEXT:          (Low: %A High: (%N + %A))
+; CHECK-NEXT:            Member: {%A,+,1}<nuw><%loop>
+; CHECK-NEXT:        Group [[GRP2]]:
+; CHECK-NEXT:          (Low: (%offset + %A) High: (%offset + %N + %A))
+; CHECK-NEXT:            Member: {(%offset + %A),+,1}<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:
+  %c = icmp sgt i64 %offset, 0
+  call void @llvm.assume(i1 %c)
+  %off = getelementptr inbounds i8, ptr %A, i64 %offset
+  call void @use(ptr noundef %off)
+  br label %loop
+
+loop:
+  %iv = phi i64 [ 0, %entry ], [ %iv.next, %loop ]
+  %gep.off = getelementptr inbounds i8, ptr %off, i64 %iv
+  %l = load i8 , ptr %gep.off, align 4
+  %add = add nsw i8 %l, 5
+  %gep = getelementptr inbounds i8, ptr %A, i64 %iv
+  store i8 %add, ptr %gep, align 4
+  %iv.next = add nuw nsw i64 %iv, 1
+  %exitcond.not = icmp eq i64 %iv.next, %N
+  br i1 %exitcond.not, label %exit, label %loop
+
+exit:
+  ret void
+}
+
+define void @offset_i32_known_positive_via_assume_forward_dep_1(ptr %A, i64 %offset, i64 %N) {
+; CHECK-LABEL: 'offset_i32_known_positive_via_assume_forward_dep_1'
+; 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:          %gep = getelementptr inbounds i32, ptr %A, i64 %iv
+; CHECK-NEXT:        Against group ([[GRP4:0x[0-9a-f]+]]):
+; CHECK-NEXT:          %gep.off = getelementptr inbounds i32, ptr %off, i64 %iv
+; CHECK-NEXT:      Grouped accesses:
+; CHECK-NEXT:        Group [[GRP3]]:
+; CHECK-NEXT:          (Low: %A High: (-3 + (4 * %N) + %A))
+; CHECK-NEXT:            Member: {%A,+,4}<nuw><%loop>
+; CHECK-NEXT:        Group [[GRP4]]:
+; CHECK-NEXT:          (Low: ((4 * %offset)<nsw> + %A) High: (-3 + (4 * %offset)<nsw> + (4 * %N) + %A))
+; CHECK-NEXT:            Member: {((4 * %offset)<nsw> + %A),+,4}<nw><%loop>
+; CHECK-EMPTY:
+; CHECK-NEXT:      Non vectorizable stores to invariant address were not found in loop.
+; CHECK-NEXT:      SCEV assumptions:
+; CHECK-NEXT:      {((4 * %offset)<nsw> + %A),+,4}<nw><%loop> Added Flags: <nusw>
+; CHECK-EMPTY:
+; CHECK-NEXT:      Expressions re-written:
+;
+entry:
+  %c = icmp sgt i64 %offset, 0
+  call void @llvm.assume(i1 %c)
+  %off = getelementptr inbounds i32, ptr %A, i64 %offset
+  call void @use(ptr noundef %off)
+
+  br label %loop
+
+loop:
+  %iv = phi i64 [ 0, %entry ], [ %iv.next, %loop ]
+  %gep.off = getelementptr inbounds i32, ptr %off, i64 %iv
+  %l = load i8 , ptr %gep.off, align 4
+  %add = add nsw i8 %l, 5
+  %gep = getelementptr inbounds i32, ptr %A, i64 %iv
+  store i8 %add, ptr %gep, align 4
+  %iv.next = add nuw nsw i64 %iv, 1
+  %exitcond.not = icmp eq i64 %iv.next, %N
+  br i1 %exitcond.not, label %exit, label %loop
+
+exit:
+  ret void
+}
+
+; TODO: %offset is known positive via assume, so we should be able to detect the
+; forward dependence.
+define void @offset_known_positive_via_assume_forward_dep_2(ptr %A, i64 %offset, i64 %N) {
+; CHECK-LABEL: 'offset_known_positive_via_assume_forward_dep_2'
+; 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 ([[GRP5:0x[0-9a-f]+]]):
+; CHECK-NEXT:          %gep = getelementptr inbounds i32, ptr %A, i64 %iv
+; CHECK-NEXT:        Against group ([[GRP6:0x[0-9a-f]+]]):
+; CHECK-NEXT:          %gep.off = getelementptr inbounds i32, ptr %off, i64 %iv
+; CHECK-NEXT:      Grouped accesses:
+; CHECK-NEXT:        Group [[GRP5]]:
+; CHECK-NEXT:          (Low: %A High: ((4 * %N) + %A))
+; CHECK-NEXT:            Member: {%A,+,4}<nuw><%loop>
+; CHECK-NEXT:        Group [[GRP6]]:
+; CHECK-NEXT:          (Low: ((4 * %offset)<nsw> + %A) High: ((4 * %offset)<nsw> + (4 * %N) + %A))
+; CHECK-NEXT:            Member: {((4 * %offset)<nsw> + %A),+,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:
+  %c = icmp sgt i64 %offset, 0
+  call void @llvm.assume(i1 %c)
+  %c.2 = icmp slt i64 %offset, 20
+  call void @llvm.assume(i1 %c.2)
+  %off = getelementptr inbounds i32, ptr %A, i64 %offset
+  br label %loop
+
+loop:
+  %iv = phi i64 [ 0, %entry ], [ %iv.next, %loop ]
+  %gep.off = getelementptr inbounds i32, ptr %off, i64 %iv
+  %l = load i32, ptr %gep.off, align 4
+  %add = add nsw i32 %l, 5
+  %gep = getelementptr inbounds i32, ptr %A, i64 %iv
+  store i32 %add, ptr %gep, align 4
+  %iv.next = add nuw nsw i64 %iv, 1
+  %exitcond.not = icmp eq i64 %iv.next, %N
+  br i1 %exitcond.not, label %exit, label %loop
+
+exit:
+  ret void
+}
+
+; The range of %offset is known via assumes, but it may be positive or negative.
+define void @offset_may_be_negative_via_assume_unknown_dep(ptr %A, i64 %offset, i64 %N) {
+; CHECK-LABEL: 'offset_may_be_negative_via_assume_unknown_dep'
+; 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 ([[GRP7:0x[0-9a-f]+]]):
+; CHECK-NEXT:          %gep.mul.2 = getelementptr inbounds i32, ptr %A, i64 %iv
+; CHECK-NEXT:        Against group ([[GRP8:0x[0-9a-f]+]]):
+; CHECK-NEXT:          %gep = getelementptr inbounds i32, ptr %off, i64 %iv
+; CHECK-NEXT:      Grouped accesses:
+; CHECK-NEXT:        Group [[GRP7]]:
+; CHECK-NEXT:          (Low: %A High: ((4 * %N) + %A))
+; CHECK-NEXT:            Member: {%A,+,4}<nuw><%loop>
+; CHECK-NEXT:        Group [[GRP8]]:
+; CHECK-NEXT:          (Low: ((4 * %offset)<nsw> + %A) High: ((4 * %offset)<nsw> + (4 * %N) + %A))
+; CHECK-NEXT:            Member: {((4 * %offset)<nsw> + %A),+,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:
+  %c = icmp sgt i64 %offset, -4
+  call void @llvm.assume(i1 %c)
+  %c.2 = icmp slt i64 %offset, 20
+  call void @llvm.assume(i1 %c.2)
+  %off = getelementptr inbounds i32, ptr %A, i64 %offset
+  br label %loop
+
+loop:
+  %iv = phi i64 [ 0, %entry ], [ %iv.next, %loop ]
+  %gep = getelementptr inbounds i32, ptr %off, i64 %iv
+  %l = load i32, ptr %gep, align 4
+  %add = add nsw i32 %l, 5
+  %gep.mul.2 = getelementptr inbounds i32, ptr %A, i64 %iv
+  store i32 %add, ptr %gep.mul.2, align 4
+  %iv.next = add nuw nsw i64 %iv, 1
+  %exitcond.not = icmp eq i64 %iv.next, %N
+  br i1 %exitcond.not, label %exit, label %loop
+
+exit:
+  ret void
+}
+
+define void @offset_no_assumes(ptr %A, i64 %offset, i64 %N) {
+; CHECK-LABEL: 'offset_no_assumes'
+; 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 ([[GRP9:0x[0-9a-f]+]]):
+; CHECK-NEXT:          %gep = getelementptr inbounds i32, ptr %A, i64 %iv
+; CHECK-NEXT:        Against group ([[GRP10:0x[0-9a-f]+]]):
+; CHECK-NEXT:          %gep.off = getelementptr inbounds i32, ptr %off, i64 %iv
+; CHECK-NEXT:      Grouped accesses:
+; CHECK-NEXT:        Group [[GRP9]]:
+; CHECK-NEXT:          (Low: %A High: ((4 * %N) + %A))
+; CHECK-NEXT:            Member: {%A,+,4}<nuw><%loop>
+; CHECK-NEXT:        Group [[GRP10]]:
+; CHECK-NEXT:          (Low: ((4 * %offset)<nsw> + %A) High: ((4 * %offset)<nsw> + (4 * %N) + %A))
+; CHECK-NEXT:            Member: {((4 * %offset)<nsw> + %A),+,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:
+  %off = getelementptr inbounds i32, ptr %A, i64 %offset
+  br label %loop
+
+loop:
+  %iv = phi i64 [ 0, %entry ], [ %iv.next, %loop ]
+  %gep.off = getelementptr inbounds i32, ptr %off, i64 %iv
+  %l = load i32, ptr %gep.off, align 4
+  %add = add nsw i32 %l, 5
+  %gep = getelementptr inbounds i32, ptr %A, i64 %iv
+  store i32 %add, ptr %gep, align 4
+  %iv.next = add nuw nsw i64 %iv, 1
+  %exitcond.not = icmp eq i64 %iv.next, %N
+  br i1 %exitcond.not, label %exit, label %loop
+
+exit:
+  ret void
+}


        


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