[llvm] f0265cc - [LoopUnroll] Ensure we can accept both `llvm.loop.unroll.full` and `llvm.loop.unroll.enable` metadata on the same loop (NFC) (#182381)

[via llvm-commits]

Author: Justin Fargnoli
Date: 2026-03-05T16:44:25Z
New Revision: f0265ccb60746e3c34254bb2e06ca62bd51b6ba2

URL: https://github.com/llvm/llvm-project/commit/f0265ccb60746e3c34254bb2e06ca62bd51b6ba2
DIFF: https://github.com/llvm/llvm-project/commit/f0265ccb60746e3c34254bb2e06ca62bd51b6ba2.diff

LOG: [LoopUnroll] Ensure we can accept both `llvm.loop.unroll.full` and `llvm.loop.unroll.enable` metadata on the same loop (NFC) (#182381)

Ensure that frontends can request both `PragmaEnable` and `PragmaFull`
semantics on a loop.

FYI: to the best of my knowledge, it's not possible to toggle both
`PragmaEnable` and `PragmaFull` via `clang`.

Added: 
    llvm/test/Transforms/LoopUnroll/full-and-enable.ll

Modified: 
    

Removed: 
    


################################################################################
diff  --git a/llvm/test/Transforms/LoopUnroll/full-and-enable.ll b/llvm/test/Transforms/LoopUnroll/full-and-enable.ll
new file mode 100644
index 0000000000000..924141717a808
--- /dev/null
+++ b/llvm/test/Transforms/LoopUnroll/full-and-enable.ll
@@ -0,0 +1,80 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
+; RUN: opt -passes=loop-unroll -S < %s | FileCheck %s
+
+define void @full_and_enable(ptr %p, i32 %n) {
+; CHECK-LABEL: define void @full_and_enable(
+; CHECK-SAME: ptr [[P:%.*]], i32 [[N:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    [[MASK:%.*]] = and i32 [[N]], 1
+; CHECK-NEXT:    [[BOUND:%.*]] = add nuw i32 [[MASK]], 1
+; CHECK-NEXT:    br label %[[LOOP:.*]]
+; CHECK:       [[LOOP]]:
+; CHECK-NEXT:    store i32 0, ptr [[P]], align 4
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ult i32 1, [[BOUND]]
+; CHECK-NEXT:    br i1 [[CMP]], label %[[LOOP_1:.*]], label %[[EXIT:.*]]
+; CHECK:       [[LOOP_1]]:
+; CHECK-NEXT:    [[PTR_1:%.*]] = getelementptr inbounds i32, ptr [[P]], i32 1
+; CHECK-NEXT:    store i32 0, ptr [[PTR_1]], align 4
+; CHECK-NEXT:    br label %[[EXIT]]
+; CHECK:       [[EXIT]]:
+; CHECK-NEXT:    ret void
+;
+entry:
+  %mask = and i32 %n, 1
+  %bound = add nuw i32 %mask, 1
+  br label %loop
+
+loop:
+  %iv = phi i32 [ 0, %entry ], [ %iv.next, %loop ]
+  %ptr = getelementptr inbounds i32, ptr %p, i32 %iv
+  store i32 0, ptr %ptr, align 4
+  %iv.next = add nuw i32 %iv, 1
+  %cmp = icmp ult i32 %iv.next, %bound
+  br i1 %cmp, label %loop, label %exit, !llvm.loop !0
+
+exit:
+  ret void
+}
+
+define void @full_only(ptr %p, i32 %n) {
+; CHECK-LABEL: define void @full_only(
+; CHECK-SAME: ptr [[P:%.*]], i32 [[N:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*]]:
+; CHECK-NEXT:    [[MASK:%.*]] = and i32 [[N]], 1
+; CHECK-NEXT:    [[BOUND:%.*]] = add nuw i32 [[MASK]], 1
+; CHECK-NEXT:    br label %[[LOOP:.*]]
+; CHECK:       [[LOOP]]:
+; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ 0, %[[ENTRY]] ], [ [[IV_NEXT:%.*]], %[[LOOP]] ]
+; CHECK-NEXT:    [[PTR:%.*]] = getelementptr inbounds i32, ptr [[P]], i32 [[IV]]
+; CHECK-NEXT:    store i32 0, ptr [[PTR]], align 4
+; CHECK-NEXT:    [[IV_NEXT]] = add nuw i32 [[IV]], 1
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ult i32 [[IV_NEXT]], [[BOUND]]
+; CHECK-NEXT:    br i1 [[CMP]], label %[[LOOP]], label %[[EXIT:.*]], !llvm.loop [[LOOP0:![0-9]+]]
+; CHECK:       [[EXIT]]:
+; CHECK-NEXT:    ret void
+;
+entry:
+  %mask = and i32 %n, 1
+  %bound = add nuw i32 %mask, 1
+  br label %loop
+
+loop:
+  %iv = phi i32 [ 0, %entry ], [ %iv.next, %loop ]
+  %ptr = getelementptr inbounds i32, ptr %p, i32 %iv
+  store i32 0, ptr %ptr, align 4
+  %iv.next = add nuw i32 %iv, 1
+  %cmp = icmp ult i32 %iv.next, %bound
+  br i1 %cmp, label %loop, label %exit, !llvm.loop !1
+
+exit:
+  ret void
+}
+
+!0 = distinct !{!0, !2, !3}
+!1 = distinct !{!1, !2}
+!2 = !{!"llvm.loop.unroll.full"}
+!3 = !{!"llvm.loop.unroll.enable"}
+;.
+; CHECK: [[LOOP0]] = distinct !{[[LOOP0]], [[META1:![0-9]+]]}
+; CHECK: [[META1]] = !{!"llvm.loop.unroll.full"}
+;.