[llvm] [LV] Add early-exit-with-store tests (PR #140899)

[David Sherwood via llvm-commits]

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@@ -0,0 +1,383 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 4
+; REQUIRES: asserts
+; RUN: opt -S < %s -p loop-vectorize -debug-only=loop-vectorize -enable-early-exit-vectorization -force-vector-width=4 -disable-output 2>&1 | FileCheck %s
+
+define i64 @loop_contains_store(ptr %dest) {
+; CHECK-LABEL: LV: Checking a loop in 'loop_contains_store'
+; CHECK:       LV: Not vectorizing: Writes to memory unsupported in early exit loops
+entry:
+  %p1 = alloca [1024 x i8]
+  call void @init_mem(ptr %p1, i64 1024)
+  br label %loop
+
+loop:
+  %index = phi i64 [ %index.next, %loop.inc ], [ 3, %entry ]
+  %arrayidx = getelementptr inbounds i32, ptr %p1, i64 %index
+  %ld1 = load i32, ptr %arrayidx, align 1
+  %arrayidx2 = getelementptr inbounds i32, ptr %dest, i64 %index
+  store i32 %ld1, ptr %arrayidx2, align 4
+  %cmp = icmp eq i32 %ld1, 1
+  br i1 %cmp, label %loop.inc, label %loop.end
+
+loop.inc:
+  %index.next = add i64 %index, 1
+  %exitcond = icmp ne i64 %index.next, 67
+  br i1 %exitcond, label %loop, label %loop.end
+
+loop.end:
+  %retval = phi i64 [ %index, %loop ], [ 67, %loop.inc ]
+  ret i64 %retval
+}
+
+define void @loop_contains_store_condition_load_has_single_user(ptr dereferenceable(40) noalias %array, ptr align 2 dereferenceable(40) readonly %pred) {
+; CHECK-LABEL: LV: Checking a loop in 'loop_contains_store_condition_load_has_single_user'
+; CHECK:       LV: Not vectorizing: Writes to memory unsupported in early exit loops.
+entry:
+  br label %for.body
+
+for.body:
+  %iv = phi i64 [ 0, %entry ], [ %iv.next, %for.inc ]
+  %st.addr = getelementptr inbounds nuw i16, ptr %array, i64 %iv
+  %data = load i16, ptr %st.addr, align 2
+  %inc = add nsw i16 %data, 1
+  store i16 %inc, ptr %st.addr, align 2
+  %ee.addr = getelementptr inbounds nuw i16, ptr %pred, i64 %iv
+  %ee.val = load i16, ptr %ee.addr, align 2
+  %ee.cond = icmp sgt i16 %ee.val, 500
+  br i1 %ee.cond, label %exit, label %for.inc
+
+for.inc:
+  %iv.next = add nuw nsw i64 %iv, 1
+  %counted.cond = icmp eq i64 %iv.next, 20
+  br i1 %counted.cond, label %exit, label %for.body
+
+exit:
+  ret void
+}
+
+define void @loop_contains_store_ee_condition_is_invariant(ptr dereferenceable(40) noalias %array, i16 %ee.val) {
+; CHECK-LABEL: LV: Checking a loop in 'loop_contains_store_ee_condition_is_invariant'
+; CHECK:       LV: Not vectorizing: Writes to memory unsupported in early exit loops.
+entry:
+  br label %for.body
+
+for.body:
+  %iv = phi i64 [ 0, %entry ], [ %iv.next, %for.inc ]
+  %st.addr = getelementptr inbounds nuw i16, ptr %array, i64 %iv
+  %data = load i16, ptr %st.addr, align 2
+  %inc = add nsw i16 %data, 1
+  store i16 %inc, ptr %st.addr, align 2
+  %ee.cond = icmp sgt i16 %ee.val, 500
+  br i1 %ee.cond, label %exit, label %for.inc
+
+for.inc:
+  %iv.next = add nuw nsw i64 %iv, 1
+  %counted.cond = icmp eq i64 %iv.next, 20
+  br i1 %counted.cond, label %exit, label %for.body
+
+exit:
+  ret void
+}
+
+define void @loop_contains_store_fcmp_condition(ptr dereferenceable(40) noalias %array, ptr align 2 dereferenceable(40) readonly %pred) {
+; CHECK-LABEL: LV: Checking a loop in 'loop_contains_store_fcmp_condition'
+; CHECK:       LV: Not vectorizing: Writes to memory unsupported in early exit loops.
+entry:
+  br label %for.body
+
+for.body:
+  %iv = phi i64 [ 0, %entry ], [ %iv.next, %for.inc ]
+  %st.addr = getelementptr inbounds nuw i16, ptr %array, i64 %iv
+  %data = load i16, ptr %st.addr, align 2
+  %inc = add nsw i16 %data, 1
+  store i16 %inc, ptr %st.addr, align 2
+  %ee.addr = getelementptr inbounds nuw half, ptr %pred, i64 %iv
+  %ee.val = load half, ptr %ee.addr, align 2
+  %ee.cond = fcmp ugt half %ee.val, 500.0
+  br i1 %ee.cond, label %exit, label %for.inc
+
+for.inc:
+  %iv.next = add nuw nsw i64 %iv, 1
+  %counted.cond = icmp eq i64 %iv.next, 20
+  br i1 %counted.cond, label %exit, label %for.body
+
+exit:
+  ret void
+}
+
+define void @loop_contains_store_safe_dependency(ptr dereferenceable(40) noalias %array, ptr align 2 dereferenceable(80) readonly %pred) {
+; CHECK-LABEL: LV: Checking a loop in 'loop_contains_store_safe_dependency'
+; CHECK:       LV: Not vectorizing: Writes to memory unsupported in early exit loops.
+entry:
+  %forward = getelementptr i16, ptr %pred, i64 -8
+  br label %for.body
+
+for.body:
+  %iv = phi i64 [ 0, %entry ], [ %iv.next, %for.inc ]
+  %st.addr = getelementptr inbounds nuw i16, ptr %array, i64 %iv
+  %data = load i16, ptr %st.addr, align 2
+  %inc = add nsw i16 %data, 1
+  store i16 %inc, ptr %st.addr, align 2
+  %ee.addr = getelementptr inbounds nuw i16, ptr %pred, i64 %iv
+  %ee.val = load i16, ptr %ee.addr, align 2
+  %ee.cond = icmp sgt i16 %ee.val, 500
+  %some.addr = getelementptr inbounds nuw i16, ptr %forward, i64 %iv
+  store i16 42, ptr %some.addr, align 2
+  br i1 %ee.cond, label %exit, label %for.inc
+
+for.inc:
+  %iv.next = add nuw nsw i64 %iv, 1
+  %counted.cond = icmp eq i64 %iv.next, 20
+  br i1 %counted.cond, label %exit, label %for.body
+
+exit:
+  ret void
+}
+
+define void @loop_contains_store_unsafe_dependency(ptr dereferenceable(40) noalias %array, ptr align 2 dereferenceable(80) readonly %pred) {
+; CHECK-LABEL: LV: Checking a loop in 'loop_contains_store_unsafe_dependency'
+; CHECK:       LV: Not vectorizing: Writes to memory unsupported in early exit loops.
+entry:
+  %unknown.offset = call i64 @get_an_unknown_offset()
+  %unknown.base = getelementptr i16, ptr %pred, i64 %unknown.offset
+  br label %for.body
+
+for.body:
+  %iv = phi i64 [ 0, %entry ], [ %iv.next, %for.inc ]
+  %st.addr = getelementptr inbounds nuw i16, ptr %array, i64 %iv
+  %data = load i16, ptr %st.addr, align 2
+  %inc = add nsw i16 %data, 1
+  store i16 %inc, ptr %st.addr, align 2
+  %ee.addr = getelementptr inbounds nuw i16, ptr %pred, i64 %iv
+  %ee.val = load i16, ptr %ee.addr, align 2
+  %ee.cond = icmp sgt i16 %ee.val, 500
+  %some.addr = getelementptr inbounds nuw i16, ptr %unknown.base, i64 %iv
+  store i16 42, ptr %some.addr, align 2
+  br i1 %ee.cond, label %exit, label %for.inc
+
+for.inc:
+  %iv.next = add nuw nsw i64 %iv, 1
+  %counted.cond = icmp eq i64 %iv.next, 20
+  br i1 %counted.cond, label %exit, label %for.body
+
+exit:
+  ret void
+}
+
+define void @loop_contains_store_assumed_bounds(ptr noalias %array, ptr readonly %pred, i32 %n) {
+; CHECK-LABEL: LV: Checking a loop in 'loop_contains_store_assumed_bounds'
+; CHECK:       LV: Not vectorizing: Writes to memory unsupported in early exit loops.
+entry:
+  %n_bytes = mul nuw nsw i32 %n, 2
+  call void @llvm.assume(i1 true) [ "align"(ptr %pred, i64 2), "dereferenceable"(ptr %pred, i32 %n_bytes) ]
+  %tc = sext i32 %n to i64
+  br label %for.body
+
+for.body:
+  %iv = phi i64 [ 0, %entry ], [ %iv.next, %for.inc ]
+  %st.addr = getelementptr inbounds nuw i16, ptr %array, i64 %iv
+  %data = load i16, ptr %st.addr, align 2
+  %inc = add nsw i16 %data, 1
+  store i16 %inc, ptr %st.addr, align 2
+  %ee.addr = getelementptr inbounds nuw i16, ptr %pred, i64 %iv
+  %ee.val = load i16, ptr %ee.addr, align 2
+  %ee.cond = icmp sgt i16 %ee.val, 500
+  br i1 %ee.cond, label %exit, label %for.inc
+
+for.inc:
+  %iv.next = add nuw nsw i64 %iv, 1
+  %counted.cond = icmp eq i64 %iv.next, %tc
+  br i1 %counted.cond, label %exit, label %for.body
+
+exit:
+  ret void
+}
+
+define void @loop_contains_store_to_pointer_with_no_deref_info(ptr noalias %array, ptr align 2 dereferenceable(40) readonly %pred) {
+; CHECK-LABEL: LV: Checking a loop in 'loop_contains_store_to_pointer_with_no_deref_info'
+; CHECK:       LV: Not vectorizing: Writes to memory unsupported in early exit loops.
+entry:
+  br label %for.body
+
+for.body:
+  %iv = phi i64 [ 0, %entry ], [ %iv.next, %for.inc ]
+  %st.addr = getelementptr inbounds nuw i16, ptr %array, i64 %iv
+  %data = load i16, ptr %st.addr, align 2
+  %inc = add nsw i16 %data, 1
+  store i16 %inc, ptr %st.addr, align 2
+  %ee.addr = getelementptr inbounds nuw i16, ptr %pred, i64 %iv
+  %ee.val = load i16, ptr %ee.addr, align 2
+  %ee.cond = icmp sgt i16 %ee.val, 500
+  br i1 %ee.cond, label %exit, label %for.inc
+
+for.inc:
+  %iv.next = add nuw nsw i64 %iv, 1
+  %counted.cond = icmp eq i64 %iv.next, 20
+  br i1 %counted.cond, label %exit, label %for.body
+
+exit:
+  ret void
+}
+
+define void @loop_contains_store_unknown_bounds(ptr noalias %array, ptr readonly %pred, i32 %n) {
----------------
david-arm wrote:

There are two problems here, right? The first is the pointers are not known to be dereferenceable at all, and the second is the trip count is unknown. If you specifically want to test the latter, perhaps it's worth marking the pointers as dereferenceable(100) or some other random number? That way the analysis code is guaranteed to get to the point where the trip count matters. I'm just a bit worried the test is relying upon the order in which we do the checks.

https://github.com/llvm/llvm-project/pull/140899