1 files changed, 60 insertions, 0 deletions
diff --git a/llvm/test/Analysis/ScalarEvolution/extract-highbits-sameconstmask.ll b/llvm/test/Analysis/ScalarEvolution/extract-highbits-sameconstmask.ll
new file mode 100644
index 00000000000..851dce65316
--- /dev/null
+++ b/llvm/test/Analysis/ScalarEvolution/extract-highbits-sameconstmask.ll
@@ -0,0 +1,60 @@
+; NOTE: Assertions have been autogenerated by utils/update_analyze_test_checks.py
+; RUN: opt -S -analyze -scalar-evolution < %s | FileCheck %s
+
+; The obvious case.
+define i32 @div(i32 %val) nounwind {
+; CHECK-LABEL: 'div'
+; CHECK-NEXT:  Classifying expressions for: @div
+; CHECK-NEXT:    %tmp1 = udiv i32 %val, 16
+; CHECK-NEXT:    -->  (%val /u 16) U: [0,268435456) S: [0,268435456)
+; CHECK-NEXT:    %tmp2 = mul i32 %tmp1, 16
+; CHECK-NEXT:    -->  (16 * (%val /u 16)) U: [0,-15) S: [0,-15)
+; CHECK-NEXT:  Determining loop execution counts for: @div
+;
+  %tmp1 = udiv i32 %val, 16
+  %tmp2 = mul i32 %tmp1, 16
+  ret i32 %tmp2
+}
+
+define i32 @sdiv(i32 %val) nounwind {
+; CHECK-LABEL: 'sdiv'
+; CHECK-NEXT:  Classifying expressions for: @sdiv
+; CHECK-NEXT:    %tmp1 = sdiv i32 %val, 16
+; CHECK-NEXT:    -->  %tmp1 U: full-set S: [-134217728,134217728)
+; CHECK-NEXT:    %tmp2 = mul i32 %tmp1, 16
+; CHECK-NEXT:    -->  (16 * %tmp1) U: [0,-15) S: [-2147483648,2147483633)
+; CHECK-NEXT:  Determining loop execution counts for: @sdiv
+;
+  %tmp1 = sdiv i32 %val, 16
+  %tmp2 = mul i32 %tmp1, 16
+  ret i32 %tmp2
+}
+
+; Or, it could be a number of equivalent patterns with mask:
+;   b) x &  (-1 << nbits)
+;   d) x >> nbits << nbits
+
+define i32 @mask_b(i32 %val) nounwind {
+; CHECK-LABEL: 'mask_b'
+; CHECK-NEXT:  Classifying expressions for: @mask_b
+; CHECK-NEXT:    %masked = and i32 %val, -16
+; CHECK-NEXT:    -->  (16 * (%val /u 16)) U: [0,-15) S: [0,-15)
+; CHECK-NEXT:  Determining loop execution counts for: @mask_b
+;
+  %masked = and i32 %val, -16
+  ret i32 %masked
+}
+
+define i32 @mask_d(i32 %val) nounwind {
+; CHECK-LABEL: 'mask_d'
+; CHECK-NEXT:  Classifying expressions for: @mask_d
+; CHECK-NEXT:    %lowbitscleared = lshr i32 %val, 4
+; CHECK-NEXT:    -->  (%val /u 16) U: [0,268435456) S: [0,268435456)
+; CHECK-NEXT:    %masked = shl i32 %lowbitscleared, 4
+; CHECK-NEXT:    -->  (16 * (%val /u 16)) U: [0,-15) S: [0,-15)
+; CHECK-NEXT:  Determining loop execution counts for: @mask_d
+;
+  %lowbitscleared = lshr i32 %val, 4
+  %masked = shl i32 %lowbitscleared, 4
+  ret i32 %masked
+}