[llvm] 3cbdae2 - [SCEV] Add tests where assumes can be used to improve tripe multiple.

[Florian Hahn via llvm-commits]

Author: Florian Hahn
Date: 2020-10-19T18:26:09+01:00
New Revision: 3cbdae22b91b94d21c0ca348e5ceea7081c9887d

URL: https://github.com/llvm/llvm-project/commit/3cbdae22b91b94d21c0ca348e5ceea7081c9887d
DIFF: https://github.com/llvm/llvm-project/commit/3cbdae22b91b94d21c0ca348e5ceea7081c9887d.diff

LOG: [SCEV] Add tests where assumes can be used to improve tripe multiple.

This patch adds a set of tests where information from assumes can be
used to improve the trip multiple.

See PR47904.

Added: 
    llvm/test/Analysis/ScalarEvolution/trip-multiple-guard-info.ll

Modified: 
    

Removed: 
    


################################################################################
diff  --git a/llvm/test/Analysis/ScalarEvolution/trip-multiple-guard-info.ll b/llvm/test/Analysis/ScalarEvolution/trip-multiple-guard-info.ll
new file mode 100644
index 000000000000..ccd03c0db3d9
--- /dev/null
+++ b/llvm/test/Analysis/ScalarEvolution/trip-multiple-guard-info.ll
@@ -0,0 +1,57 @@
+; NOTE: Assertions have been autogenerated by utils/update_analyze_test_checks.py
+; RUN: opt -analyze -scalar-evolution %s -enable-new-pm=0 | FileCheck %s
+; RUN: opt -passes='print<scalar-evolution>' -disable-output %s 2>&1 | FileCheck %s
+
+; Tests for PR47904.
+
+define void @test_trip_multiple_4(i32 %num) {
+; CHECK-LABEL: @test_trip_multiple_4
+; CHECK:       Loop %for.body: backedge-taken count is (-1 + %num)
+; CHECK-NEXT:  Loop %for.body: max backedge-taken count is -2
+; CHECK-NEXT:  Loop %for.body: Predicated backedge-taken count is (-1 + %num)
+; CHECK:       Loop %for.body: Trip multiple is 1
+;
+entry:
+  %u = urem i32 %num, 4
+  %cmp = icmp eq i32 %u, 0
+  tail call void @llvm.assume(i1 %cmp)
+  %cmp.1 = icmp uge i32 %num, 4
+  tail call void @llvm.assume(i1 %cmp.1)
+  br label %for.body
+
+for.body:
+  %i.010 = phi i32 [ 0, %entry ], [ %inc, %for.body ]
+  %inc = add nuw nsw i32 %i.010, 1
+  %cmp2 = icmp ult i32 %inc, %num
+  br i1 %cmp2, label %for.body, label %exit
+
+exit:
+  ret void
+}
+
+define void @test_trip_multiple_5(i32 %num) {
+; CHECK-LABEL: @test_trip_multiple_5
+; CHECK:       Loop %for.body: backedge-taken count is (-1 + %num)
+; CHECK-NEXT:  Loop %for.body: max backedge-taken count is -2
+; CHECK-NEXT:  Loop %for.body: Predicated backedge-taken count is (-1 + %num)
+; CHECK:       Loop %for.body: Trip multiple is 1
+;
+entry:
+  %u = urem i32 %num, 5
+  %cmp = icmp eq i32 %u, 0
+  tail call void @llvm.assume(i1 %cmp)
+  %cmp.1 = icmp uge i32 %num, 5
+  tail call void @llvm.assume(i1 %cmp.1)
+  br label %for.body
+
+for.body:
+  %i.010 = phi i32 [ 0, %entry ], [ %inc, %for.body ]
+  %inc = add nuw nsw i32 %i.010, 1
+  %cmp2 = icmp ult i32 %inc, %num
+  br i1 %cmp2, label %for.body, label %exit
+
+exit:
+  ret void
+}
+
+declare void @llvm.assume(i1)