1 files changed, 68 insertions, 0 deletions
diff --git a/llvm/test/Analysis/ScalarEvolution/extract-highbits-variablemask.ll b/llvm/test/Analysis/ScalarEvolution/extract-highbits-variablemask.ll
new file mode 100644
index 00000000000..56d86f0309e
--- /dev/null
+++ b/llvm/test/Analysis/ScalarEvolution/extract-highbits-variablemask.ll
@@ -0,0 +1,68 @@
+; NOTE: Assertions have been autogenerated by utils/update_analyze_test_checks.py
+; RUN: opt -S -analyze -scalar-evolution < %s | FileCheck %s
+
+; These testcases aren't *identical* but they have the same/similar meaning.
+
+; The obvious case.
+define i32 @div(i32 %val, i32 %num) nounwind {
+; CHECK-LABEL: 'div'
+; CHECK-NEXT:  Classifying expressions for: @div
+; CHECK-NEXT:    %tmp1 = udiv i32 %val, %num
+; CHECK-NEXT:    -->  (%val /u %num) U: full-set S: full-set
+; CHECK-NEXT:    %tmp2 = mul i32 %tmp1, %num
+; CHECK-NEXT:    -->  ((%val /u %num) * %num) U: full-set S: full-set
+; CHECK-NEXT:  Determining loop execution counts for: @div
+;
+  %tmp1 = udiv i32 %val, %num
+  %tmp2 = mul i32 %tmp1, %num
+  ret i32 %tmp2
+}
+
+define i32 @sdiv(i32 %val, i32 %num) nounwind {
+; CHECK-LABEL: 'sdiv'
+; CHECK-NEXT:  Classifying expressions for: @sdiv
+; CHECK-NEXT:    %tmp1 = sdiv i32 %val, %num
+; CHECK-NEXT:    -->  %tmp1 U: full-set S: full-set
+; CHECK-NEXT:    %tmp2 = mul i32 %tmp1, %num
+; CHECK-NEXT:    -->  (%num * %tmp1) U: full-set S: full-set
+; CHECK-NEXT:  Determining loop execution counts for: @sdiv
+;
+  %tmp1 = sdiv i32 %val, %num
+  %tmp2 = mul i32 %tmp1, %num
+  ret i32 %tmp2
+}
+
+; Or, it could be a number of equivalent patterns with mask:
+;   b) x &  (-1 << nbits)
+;   d) x >> (32 - y) << (32 - y)
+
+define i32 @mask_b(i32 %val, i32 %numlowbits) nounwind {
+; CHECK-LABEL: 'mask_b'
+; CHECK-NEXT:  Classifying expressions for: @mask_b
+; CHECK-NEXT:    %mask = shl i32 -1, %numlowbits
+; CHECK-NEXT:    -->  %mask U: full-set S: full-set
+; CHECK-NEXT:    %masked = and i32 %mask, %val
+; CHECK-NEXT:    -->  %masked U: full-set S: full-set
+; CHECK-NEXT:  Determining loop execution counts for: @mask_b
+;
+  %mask = shl i32 -1, %numlowbits
+  %masked = and i32 %mask, %val
+  ret i32 %masked
+}
+
+define i32 @mask_d(i32 %val, i32 %lowbits) nounwind {
+; CHECK-LABEL: 'mask_d'
+; CHECK-NEXT:  Classifying expressions for: @mask_d
+; CHECK-NEXT:    %numlowbits = sub i32 32, %lowbits
+; CHECK-NEXT:    -->  (32 + (-1 * %lowbits)) U: full-set S: full-set
+; CHECK-NEXT:    %lowbitscleared = lshr i32 %val, %numlowbits
+; CHECK-NEXT:    -->  %lowbitscleared U: full-set S: full-set
+; CHECK-NEXT:    %masked = shl i32 %lowbitscleared, %numlowbits
+; CHECK-NEXT:    -->  %masked U: full-set S: full-set
+; CHECK-NEXT:  Determining loop execution counts for: @mask_d
+;
+  %numlowbits = sub i32 32, %lowbits
+  %lowbitscleared = lshr i32 %val, %numlowbits
+  %masked = shl i32 %lowbitscleared, %numlowbits
+  ret i32 %masked
+}