[llvm] 719e7be - [LoopPeel] Add tests for last iteration peeling of min/max intrinsics

[Philip Reames via llvm-commits]

Author: Philip Reames
Date: 2025-06-10T13:08:36-07:00
New Revision: 719e7bea8af3335f8d7c46205ce8357baf4fa11d

URL: https://github.com/llvm/llvm-project/commit/719e7bea8af3335f8d7c46205ce8357baf4fa11d
DIFF: https://github.com/llvm/llvm-project/commit/719e7bea8af3335f8d7c46205ce8357baf4fa11d.diff

LOG: [LoopPeel] Add tests for last iteration peeling of min/max intrinsics

Added: 
    llvm/test/Transforms/LoopUnroll/peel-last-iteration-minmax.ll

Modified: 
    

Removed: 
    


################################################################################
diff  --git a/llvm/test/Transforms/LoopUnroll/peel-last-iteration-minmax.ll b/llvm/test/Transforms/LoopUnroll/peel-last-iteration-minmax.ll
new file mode 100644
index 0000000000000..cd098e123b5f6
--- /dev/null
+++ b/llvm/test/Transforms/LoopUnroll/peel-last-iteration-minmax.ll
@@ -0,0 +1,137 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
+; RUN: opt -p loop-unroll -unroll-full-max-count=0 -S %s | FileCheck %s
+
+declare void @foo(i32)
+
+define i32 @umin_unit_step() {
+; CHECK-LABEL: define i32 @umin_unit_step() {
+; CHECK-NEXT:  [[ENTRY:.*]]:
+; CHECK-NEXT:    br label %[[LOOP:.*]]
+; CHECK:       [[LOOP]]:
+; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ 0, %[[ENTRY]] ], [ [[IV_NEXT:%.*]], %[[LOOP]] ]
+; CHECK-NEXT:    [[SUB:%.*]] = sub i32 1024, [[IV]]
+; CHECK-NEXT:    [[MINMAX:%.*]] = call i32 @llvm.umin.i32(i32 [[SUB]], i32 1)
+; CHECK-NEXT:    call void @foo(i32 [[MINMAX]])
+; CHECK-NEXT:    [[IV_NEXT]] = add nuw nsw i32 [[IV]], 1
+; CHECK-NEXT:    [[EC:%.*]] = icmp ne i32 [[IV_NEXT]], 1024
+; CHECK-NEXT:    br i1 [[EC]], label %[[LOOP]], label %[[EXIT:.*]]
+; CHECK:       [[EXIT]]:
+; CHECK-NEXT:    [[MINMAX_LCSSA:%.*]] = phi i32 [ [[MINMAX]], %[[LOOP]] ]
+; CHECK-NEXT:    ret i32 [[MINMAX_LCSSA]]
+;
+entry:
+  br label %loop
+
+loop:
+  %iv = phi i32 [ 0, %entry ], [ %iv.next, %loop ]
+  %sub = sub i32 1024, %iv
+  %minmax = call i32 @llvm.umin(i32 %sub, i32 1)
+  call void @foo(i32 %minmax)
+  %iv.next = add nuw nsw i32 %iv, 1
+  %ec = icmp ne i32 %iv.next, 1024
+  br i1 %ec, label %loop, label %exit
+
+exit:
+  %minmax.lcssa = phi i32 [ %minmax, %loop ]
+  ret i32 %minmax.lcssa
+}
+
+define i32 @smin_unit_step() {
+; CHECK-LABEL: define i32 @smin_unit_step() {
+; CHECK-NEXT:  [[ENTRY:.*]]:
+; CHECK-NEXT:    br label %[[LOOP:.*]]
+; CHECK:       [[LOOP]]:
+; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ 0, %[[ENTRY]] ], [ [[IV_NEXT:%.*]], %[[LOOP]] ]
+; CHECK-NEXT:    [[SUB:%.*]] = sub i32 1024, [[IV]]
+; CHECK-NEXT:    [[MINMAX:%.*]] = call i32 @llvm.smin.i32(i32 [[SUB]], i32 1)
+; CHECK-NEXT:    call void @foo(i32 [[MINMAX]])
+; CHECK-NEXT:    [[IV_NEXT]] = add nuw nsw i32 [[IV]], 1
+; CHECK-NEXT:    [[EC_PEEL:%.*]] = icmp ne i32 [[IV_NEXT]], 1024
+; CHECK-NEXT:    br i1 [[EC_PEEL]], label %[[LOOP]], label %[[EXIT:.*]]
+; CHECK:       [[EXIT]]:
+; CHECK-NEXT:    [[MINMAX_LCSSA:%.*]] = phi i32 [ [[MINMAX]], %[[LOOP]] ]
+; CHECK-NEXT:    ret i32 [[MINMAX_LCSSA]]
+;
+entry:
+  br label %loop
+
+loop:
+  %iv = phi i32 [ 0, %entry ], [ %iv.next, %loop ]
+  %sub = sub i32 1024, %iv
+  %minmax = call i32 @llvm.smin(i32 %sub, i32 1)
+  call void @foo(i32 %minmax)
+  %iv.next = add nuw nsw i32 %iv, 1
+  %ec = icmp ne i32 %iv.next, 1024
+  br i1 %ec, label %loop, label %exit
+
+exit:
+  %minmax.lcssa = phi i32 [ %minmax, %loop ]
+  ret i32 %minmax.lcssa
+}
+
+define i32 @smax_unit_step() {
+; CHECK-LABEL: define i32 @smax_unit_step() {
+; CHECK-NEXT:  [[ENTRY:.*]]:
+; CHECK-NEXT:    br label %[[LOOP:.*]]
+; CHECK:       [[LOOP]]:
+; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ 0, %[[ENTRY]] ], [ [[IV_NEXT:%.*]], %[[LOOP]] ]
+; CHECK-NEXT:    [[SUB:%.*]] = sub i32 1024, [[IV]]
+; CHECK-NEXT:    [[MINMAX:%.*]] = call i32 @llvm.smax.i32(i32 [[SUB]], i32 1)
+; CHECK-NEXT:    call void @foo(i32 [[MINMAX]])
+; CHECK-NEXT:    [[IV_NEXT]] = add nuw nsw i32 [[IV]], 1
+; CHECK-NEXT:    [[EC_PEEL:%.*]] = icmp ne i32 [[IV_NEXT]], 1024
+; CHECK-NEXT:    br i1 [[EC_PEEL]], label %[[LOOP]], label %[[EXIT:.*]]
+; CHECK:       [[EXIT]]:
+; CHECK-NEXT:    [[MINMAX_LCSSA:%.*]] = phi i32 [ [[MINMAX]], %[[LOOP]] ]
+; CHECK-NEXT:    ret i32 [[MINMAX_LCSSA]]
+;
+entry:
+  br label %loop
+
+loop:
+  %iv = phi i32 [ 0, %entry ], [ %iv.next, %loop ]
+  %sub = sub i32 1024, %iv
+  %minmax = call i32 @llvm.smax(i32 %sub, i32 1)
+  call void @foo(i32 %minmax)
+  %iv.next = add nuw nsw i32 %iv, 1
+  %ec = icmp ne i32 %iv.next, 1024
+  br i1 %ec, label %loop, label %exit
+
+exit:
+  %minmax.lcssa = phi i32 [ %minmax, %loop ]
+  ret i32 %minmax.lcssa
+}
+
+define i32 @umax_unit_step() {
+; CHECK-LABEL: define i32 @umax_unit_step() {
+; CHECK-NEXT:  [[ENTRY:.*]]:
+; CHECK-NEXT:    br label %[[LOOP:.*]]
+; CHECK:       [[LOOP]]:
+; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ 0, %[[ENTRY]] ], [ [[IV_NEXT:%.*]], %[[LOOP]] ]
+; CHECK-NEXT:    [[SUB:%.*]] = sub i32 1024, [[IV]]
+; CHECK-NEXT:    [[MINMAX:%.*]] = call i32 @llvm.umax.i32(i32 [[SUB]], i32 1)
+; CHECK-NEXT:    call void @foo(i32 [[MINMAX]])
+; CHECK-NEXT:    [[IV_NEXT]] = add nuw nsw i32 [[IV]], 1
+; CHECK-NEXT:    [[EC:%.*]] = icmp ne i32 [[IV_NEXT]], 1024
+; CHECK-NEXT:    br i1 [[EC]], label %[[LOOP]], label %[[EXIT:.*]]
+; CHECK:       [[EXIT]]:
+; CHECK-NEXT:    [[MINMAX_LCSSA:%.*]] = phi i32 [ [[MINMAX]], %[[LOOP]] ]
+; CHECK-NEXT:    ret i32 [[MINMAX_LCSSA]]
+;
+entry:
+  br label %loop
+
+loop:
+  %iv = phi i32 [ 0, %entry ], [ %iv.next, %loop ]
+  %sub = sub i32 1024, %iv
+  %minmax = call i32 @llvm.umax(i32 %sub, i32 1)
+  call void @foo(i32 %minmax)
+  %iv.next = add nuw nsw i32 %iv, 1
+  %ec = icmp ne i32 %iv.next, 1024
+  br i1 %ec, label %loop, label %exit
+
+exit:
+  %minmax.lcssa = phi i32 [ %minmax, %loop ]
+  ret i32 %minmax.lcssa
+}
+