[llvm] [LV] Use branch_weights metadata in getPredBlockCostDivisor test. NFC (PR #171299)

[Luke Lau via llvm-commits]

https://github.com/lukel97 updated https://github.com/llvm/llvm-project/pull/171299

>From 0565ab8de914071ec1511bfe8797c41f7a012e13 Mon Sep 17 00:00:00 2001
From: Luke Lau <luke at igalia.com>
Date: Tue, 9 Dec 2025 16:44:13 +0800
Subject: [PATCH 1/3] [LV] Use branch_weights metadata in
 getPredBlockCostDivisor test. NFC

This is more reliable in the event that the trivial fcmp gets folded away.
---
 .../LoopVectorize/AArch64/predicated-costs.ll          | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/llvm/test/Transforms/LoopVectorize/AArch64/predicated-costs.ll b/llvm/test/Transforms/LoopVectorize/AArch64/predicated-costs.ll
index 7787e927d24ff..153ee2377955d 100644
--- a/llvm/test/Transforms/LoopVectorize/AArch64/predicated-costs.ll
+++ b/llvm/test/Transforms/LoopVectorize/AArch64/predicated-costs.ll
@@ -442,7 +442,7 @@ exit:
 ; low, so the discount in getPredBlockCostDivisor is high enough to not fit in
 ; uint32_t. Make sure we return uint64_t which fits all possible BlockFrequency
 ; values.
-define void @getPredBlockCostDivisor_truncate(i32 %0) {
+define void @getPredBlockCostDivisor_truncate(i32 %0, i1 %c1, i1 %c2) {
 ; CHECK-LABEL: define void @getPredBlockCostDivisor_truncate(
 ; CHECK-SAME: i32 [[TMP0:%.*]]) {
 ; CHECK-NEXT:  [[ENTRY:.*]]:
@@ -468,12 +468,10 @@ entry:
 
 loop:
   %iv = phi i32 [ %0, %entry ], [ %iv.next, %latch ]
-  %isnan.1 = fcmp uno double 0.000000e+00, 0.000000e+00
-  br i1 %isnan.1, label %if.1, label %latch
+  br i1 %c1, label %if.1, label %latch, !prof !4
 
 if.1:
-  %isnan.2 = fcmp uno double 0.000000e+00, 0.000000e+00
-  br i1 %isnan.2, label %if.2, label %latch
+  br i1 %c2, label %if.2, label %latch, !prof !4
 
 if.2:
   br label %latch
@@ -487,6 +485,8 @@ exit:
   ret void
 }
 
+!4 = !{!"branch_weights", i32 0, i32 1}
+
 ;.
 ; CHECK: [[META0]] = !{[[META1:![0-9]+]]}
 ; CHECK: [[META1]] = distinct !{[[META1]], [[META2:![0-9]+]]}

>From 4763dc0d607646fcfedf0b2c85898d0599fbdc2f Mon Sep 17 00:00:00 2001
From: Luke Lau <luke at igalia.com>
Date: Tue, 9 Dec 2025 17:17:59 +0800
Subject: [PATCH 2/3] Fix utc lines

---
 .../Transforms/LoopVectorize/AArch64/predicated-costs.ll | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/llvm/test/Transforms/LoopVectorize/AArch64/predicated-costs.ll b/llvm/test/Transforms/LoopVectorize/AArch64/predicated-costs.ll
index 153ee2377955d..28f206e5c7820 100644
--- a/llvm/test/Transforms/LoopVectorize/AArch64/predicated-costs.ll
+++ b/llvm/test/Transforms/LoopVectorize/AArch64/predicated-costs.ll
@@ -444,16 +444,14 @@ exit:
 ; values.
 define void @getPredBlockCostDivisor_truncate(i32 %0, i1 %c1, i1 %c2) {
 ; CHECK-LABEL: define void @getPredBlockCostDivisor_truncate(
-; CHECK-SAME: i32 [[TMP0:%.*]]) {
+; CHECK-SAME: i32 [[TMP0:%.*]], i1 [[C1:%.*]], i1 [[C2:%.*]]) {
 ; CHECK-NEXT:  [[ENTRY:.*]]:
 ; CHECK-NEXT:    br label %[[LOOP:.*]]
 ; CHECK:       [[LOOP]]:
 ; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[TMP0]], %[[ENTRY]] ], [ [[IV_NEXT:%.*]], %[[LATCH:.*]] ]
-; CHECK-NEXT:    [[ISNAN_1:%.*]] = fcmp uno double 0.000000e+00, 0.000000e+00
-; CHECK-NEXT:    br i1 [[ISNAN_1]], label %[[IF_1:.*]], label %[[LATCH]]
+; CHECK-NEXT:    br i1 [[C1]], label %[[IF_1:.*]], label %[[LATCH]], !prof [[PROF15:![0-9]+]]
 ; CHECK:       [[IF_1]]:
-; CHECK-NEXT:    [[ISNAN_2:%.*]] = fcmp uno double 0.000000e+00, 0.000000e+00
-; CHECK-NEXT:    br i1 [[ISNAN_2]], label %[[IF_2:.*]], label %[[LATCH]]
+; CHECK-NEXT:    br i1 [[C2]], label %[[IF_2:.*]], label %[[LATCH]], !prof [[PROF15]]
 ; CHECK:       [[IF_2]]:
 ; CHECK-NEXT:    br label %[[LATCH]]
 ; CHECK:       [[LATCH]]:
@@ -503,4 +501,5 @@ exit:
 ; CHECK: [[LOOP12]] = distinct !{[[LOOP12]], [[META9]], [[META10]]}
 ; CHECK: [[LOOP13]] = distinct !{[[LOOP13]], [[META10]], [[META11]]}
 ; CHECK: [[LOOP14]] = distinct !{[[LOOP14]], [[META11]], [[META10]]}
+; CHECK: [[PROF15]] = !{!"branch_weights", i32 0, i32 1}
 ;.

>From 3313dc78512502e6bc7026a96b47689e3acdf3ed Mon Sep 17 00:00:00 2001
From: Luke Lau <luke at igalia.com>
Date: Wed, 10 Dec 2025 13:41:07 +0800
Subject: [PATCH 3/3] Add in a store

---
 .../Transforms/LoopVectorize/AArch64/predicated-costs.ll  | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/llvm/test/Transforms/LoopVectorize/AArch64/predicated-costs.ll b/llvm/test/Transforms/LoopVectorize/AArch64/predicated-costs.ll
index 28f206e5c7820..14398eebc6674 100644
--- a/llvm/test/Transforms/LoopVectorize/AArch64/predicated-costs.ll
+++ b/llvm/test/Transforms/LoopVectorize/AArch64/predicated-costs.ll
@@ -442,9 +442,9 @@ exit:
 ; low, so the discount in getPredBlockCostDivisor is high enough to not fit in
 ; uint32_t. Make sure we return uint64_t which fits all possible BlockFrequency
 ; values.
-define void @getPredBlockCostDivisor_truncate(i32 %0, i1 %c1, i1 %c2) {
+define void @getPredBlockCostDivisor_truncate(i32 %0, i1 %c1, i1 %c2, ptr %p) {
 ; CHECK-LABEL: define void @getPredBlockCostDivisor_truncate(
-; CHECK-SAME: i32 [[TMP0:%.*]], i1 [[C1:%.*]], i1 [[C2:%.*]]) {
+; CHECK-SAME: i32 [[TMP0:%.*]], i1 [[C1:%.*]], i1 [[C2:%.*]], ptr [[P:%.*]]) {
 ; CHECK-NEXT:  [[ENTRY:.*]]:
 ; CHECK-NEXT:    br label %[[LOOP:.*]]
 ; CHECK:       [[LOOP]]:
@@ -453,6 +453,8 @@ define void @getPredBlockCostDivisor_truncate(i32 %0, i1 %c1, i1 %c2) {
 ; CHECK:       [[IF_1]]:
 ; CHECK-NEXT:    br i1 [[C2]], label %[[IF_2:.*]], label %[[LATCH]], !prof [[PROF15]]
 ; CHECK:       [[IF_2]]:
+; CHECK-NEXT:    [[GEP:%.*]] = getelementptr i32, ptr [[P]], i32 [[IV]]
+; CHECK-NEXT:    store i32 0, ptr [[GEP]], align 4
 ; CHECK-NEXT:    br label %[[LATCH]]
 ; CHECK:       [[LATCH]]:
 ; CHECK-NEXT:    [[IV_NEXT]] = add i32 [[IV]], 1
@@ -472,6 +474,8 @@ if.1:
   br i1 %c2, label %if.2, label %latch, !prof !4
 
 if.2:
+  %gep = getelementptr i32, ptr %p, i32 %iv
+  store i32 0, ptr %gep
   br label %latch
 
 latch: