[llvm] [NFC][LV] Improve ee with sideeffects legality test (PR #158275)

[Graham Hunter via llvm-commits]

https://github.com/huntergr-arm updated https://github.com/llvm/llvm-project/pull/158275

>From 38c5072217a8a21098cffd63079a500b8329e0e2 Mon Sep 17 00:00:00 2001
From: Graham Hunter <graham.hunter at arm.com>
Date: Fri, 12 Sep 2025 11:09:58 +0000
Subject: [PATCH 1/3] [NFC][LV] Improve ee with sideeffects legality test

---
 .../early_exit_store_legality.ll              | 39 ++++++++-----------
 1 file changed, 17 insertions(+), 22 deletions(-)

diff --git a/llvm/test/Transforms/LoopVectorize/early_exit_store_legality.ll b/llvm/test/Transforms/LoopVectorize/early_exit_store_legality.ll
index 4226c5d9e650b..0f5f8876b6ef1 100644
--- a/llvm/test/Transforms/LoopVectorize/early_exit_store_legality.ll
+++ b/llvm/test/Transforms/LoopVectorize/early_exit_store_legality.ll
@@ -604,36 +604,31 @@ exit:
 
 ;; ICE was caused by assert for the load used in the uncountable exit condition
 ;; being guaranteed to execute.
- at e = external addrspace(21) global [4 x i8]
-define void @crash_conditional_load_for_uncountable_exit() {
+ at ee.global = external global [4 x i8]
+define void @crash_conditional_load_for_uncountable_exit(ptr dereferenceable(40) noalias %store.area) {
 ; CHECK-LABEL: LV: Checking a loop in 'crash_conditional_load_for_uncountable_exit'
 ; CHECK:       LV: Not vectorizing: Load for uncountable exit not guaranteed to execute.
 entry:
-  br label %cont
-
-handler.out_of_bounds:
-  unreachable
+  br label %for.body
 
-cont:
-  %h.06 = phi i64 [ 0, %entry ], [ %inc, %a.exit ]
-  %arrayidx = getelementptr i8, ptr addrspace(21) @e, i64 %h.06
-  br i1 false, label %cont1, label %handler.type_mismatch
+for.body:
+  %iv = phi i64 [ 0, %entry ], [ %iv.next, %for.inc ]
+  %ee.addr = getelementptr i8, ptr @ee.global, i64 %iv
+  br i1 false, label %ee.block, label %invalid.block
 
-handler.type_mismatch:
-  unreachable
+ee.block:
+  %ee.val = load i8, ptr %ee.addr, align 1
+  store i16 0, ptr %store.area, align 2
+  %ee.cmp = icmp eq i8 %ee.val, 0
+  br i1 %ee.cmp, label %for.inc, label %invalid.block
 
-cont1:
-  %0 = load i8, ptr addrspace(21) %arrayidx, align 1
-  store i16 0, ptr null, align 2
-  %cmp.not.i.i = icmp eq i8 %0, 0
-  br i1 %cmp.not.i.i, label %a.exit, label %if.then.i.i
+for.inc:
+  %iv.next = add nuw nsw i64 %iv, 1
+  %counted.cond = icmp eq i64 %iv.next, 10
+  br i1 %counted.cond, label %invalid.block, label %for.body
 
-if.then.i.i:
+invalid.block:
   unreachable
-
-a.exit:
-  %inc = add i64 %h.06, 1
-  br i1 true, label %handler.out_of_bounds, label %cont
 }
 
 

>From f3f27ce6194ca42407e334a109137e70cd38ca0a Mon Sep 17 00:00:00 2001
From: Graham Hunter <graham.hunter at arm.com>
Date: Tue, 16 Sep 2025 10:28:17 +0000
Subject: [PATCH 2/3] Added variant with ptr via argument

---
 .../early_exit_store_legality.ll              | 26 +++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/llvm/test/Transforms/LoopVectorize/early_exit_store_legality.ll b/llvm/test/Transforms/LoopVectorize/early_exit_store_legality.ll
index 0f5f8876b6ef1..4cf71a610dcdf 100644
--- a/llvm/test/Transforms/LoopVectorize/early_exit_store_legality.ll
+++ b/llvm/test/Transforms/LoopVectorize/early_exit_store_legality.ll
@@ -631,6 +631,32 @@ invalid.block:
   unreachable
 }
 
+define void @crash_conditional_load_for_uncountable_exit_argptr(ptr dereferenceable(40) noalias %store.area, ptr dereferenceable(4) %load.area) {
+; CHECK-LABEL: LV: Checking a loop in 'crash_conditional_load_for_uncountable_exit_argptr'
+; CHECK:       LV: Not vectorizing: Load for uncountable exit not guaranteed to execute.
+entry:
+  br label %for.body
+
+for.body:
+  %iv = phi i64 [ 0, %entry ], [ %iv.next, %for.inc ]
+  %ee.addr = getelementptr i8, ptr %load.area, i64 %iv
+  br i1 false, label %ee.block, label %invalid.block
+
+ee.block:
+  %ee.val = load i8, ptr %ee.addr, align 1
+  store i16 0, ptr %store.area, align 2
+  %ee.cmp = icmp eq i8 %ee.val, 0
+  br i1 %ee.cmp, label %for.inc, label %invalid.block
+
+for.inc:
+  %iv.next = add nuw nsw i64 %iv, 1
+  %counted.cond = icmp eq i64 %iv.next, 10
+  br i1 %counted.cond, label %invalid.block, label %for.body
+
+invalid.block:
+  unreachable
+}
+
 
 declare void @init_mem(ptr, i64);
 declare i64 @get_an_unknown_offset();

>From c838536c65a2afdd913ab97398f55e555128b73b Mon Sep 17 00:00:00 2001
From: Graham Hunter <graham.hunter at arm.com>
Date: Tue, 16 Sep 2025 12:14:55 +0000
Subject: [PATCH 3/3] Use an argument for branch condition instead of false

---
 .../Transforms/LoopVectorize/early_exit_store_legality.ll   | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/llvm/test/Transforms/LoopVectorize/early_exit_store_legality.ll b/llvm/test/Transforms/LoopVectorize/early_exit_store_legality.ll
index 4cf71a610dcdf..4e8b8e51df6c2 100644
--- a/llvm/test/Transforms/LoopVectorize/early_exit_store_legality.ll
+++ b/llvm/test/Transforms/LoopVectorize/early_exit_store_legality.ll
@@ -631,16 +631,16 @@ invalid.block:
   unreachable
 }
 
-define void @crash_conditional_load_for_uncountable_exit_argptr(ptr dereferenceable(40) noalias %store.area, ptr dereferenceable(4) %load.area) {
+define void @crash_conditional_load_for_uncountable_exit_argptr(ptr dereferenceable(40) noalias %store.area, ptr dereferenceable(4) %load.area, i1 %skip.cond) {
 ; CHECK-LABEL: LV: Checking a loop in 'crash_conditional_load_for_uncountable_exit_argptr'
-; CHECK:       LV: Not vectorizing: Load for uncountable exit not guaranteed to execute.
+; CHECK:       LV: Not vectorizing: Loop has too many uncountable exits.
 entry:
   br label %for.body
 
 for.body:
   %iv = phi i64 [ 0, %entry ], [ %iv.next, %for.inc ]
   %ee.addr = getelementptr i8, ptr %load.area, i64 %iv
-  br i1 false, label %ee.block, label %invalid.block
+  br i1 %skip.cond, label %ee.block, label %invalid.block
 
 ee.block:
   %ee.val = load i8, ptr %ee.addr, align 1