1 files changed, 147 insertions, 0 deletions
diff --git a/llvm/test/Transforms/StraightLineStrengthReduce/slsr-mul.ll b/llvm/test/Transforms/StraightLineStrengthReduce/slsr-mul.ll
new file mode 100644
index 00000000000..56b1d1fc5cd
--- /dev/null
+++ b/llvm/test/Transforms/StraightLineStrengthReduce/slsr-mul.ll
@@ -0,0 +1,147 @@
+; RUN: opt < %s -slsr -gvn -S | FileCheck %s
+
+target datalayout = "e-i64:64-v16:16-v32:32-n16:32:64"
+
+define void @slsr1(i32 %b, i32 %s) {
+; CHECK-LABEL: @slsr1(
+  ; foo(b * s);
+  %mul0 = mul i32 %b, %s
+; CHECK: mul i32
+; CHECK-NOT: mul i32
+  call void @foo(i32 %mul0)
+
+  ; foo((b + 1) * s);
+  %b1 = add i32 %b, 1
+  %mul1 = mul i32 %b1, %s
+  call void @foo(i32 %mul1)
+
+  ; foo((b + 2) * s);
+  %b2 = add i32 %b, 2
+  %mul2 = mul i32 %b2, %s
+  call void @foo(i32 %mul2)
+
+  ret void
+}
+
+define void @non_canonicalized(i32 %b, i32 %s) {
+; CHECK-LABEL: @non_canonicalized(
+  ; foo(b * s);
+  %mul0 = mul i32 %b, %s
+; CHECK: mul i32
+; CHECK-NOT: mul i32
+  call void @foo(i32 %mul0)
+
+  ; foo((1 + b) * s);
+  %b1 = add i32 1, %b
+  %mul1 = mul i32 %b1, %s
+  call void @foo(i32 %mul1)
+
+  ; foo((2 + b) * s);
+  %b2 = add i32 2, %b
+  %mul2 = mul i32 %b2, %s
+  call void @foo(i32 %mul2)
+
+  ret void
+}
+
+define void @or(i32 %a, i32 %s) {
+  %b = shl i32 %a, 1
+; CHECK-LABEL: @or(
+  ; foo(b * s);
+  %mul0 = mul i32 %b, %s
+; CHECK: [[base:[^ ]+]] = mul i32
+  call void @foo(i32 %mul0)
+
+  ; foo((b | 1) * s);
+  %b1 = or i32 %b, 1
+  %mul1 = mul i32 %b1, %s
+; CHECK: add i32 [[base]], %s
+  call void @foo(i32 %mul1)
+
+  ; foo((b | 2) * s);
+  %b2 = or i32 %b, 2
+  %mul2 = mul i32 %b2, %s
+; CHECK: mul i32 %b2, %s
+  call void @foo(i32 %mul2)
+
+  ret void
+}
+
+; foo(a * b)
+; foo((a + 1) * b)
+; foo(a * (b + 1))
+; foo((a + 1) * (b + 1))
+define void @slsr2(i32 %a, i32 %b) {
+; CHECK-LABEL: @slsr2(
+  %a1 = add i32 %a, 1
+  %b1 = add i32 %b, 1
+  %mul0 = mul i32 %a, %b
+; CHECK: mul i32
+; CHECK-NOT: mul i32
+  %mul1 = mul i32 %a1, %b
+  %mul2 = mul i32 %a, %b1
+  %mul3 = mul i32 %a1, %b1
+
+  call void @foo(i32 %mul0)
+  call void @foo(i32 %mul1)
+  call void @foo(i32 %mul2)
+  call void @foo(i32 %mul3)
+
+  ret void
+}
+
+; The bump is a multiple of the stride.
+;
+; foo(b * s);
+; foo((b + 2) * s);
+; foo((b + 4) * s);
+;   =>
+; mul0 = b * s;
+; bump = s * 2;
+; mul1 = mul0 + bump; // GVN ensures mul1 and mul2 use the same bump.
+; mul2 = mul1 + bump;
+define void @slsr3(i32 %b, i32 %s) {
+; CHECK-LABEL: @slsr3(
+  %mul0 = mul i32 %b, %s
+; CHECK: mul i32
+  call void @foo(i32 %mul0)
+
+  %b1 = add i32 %b, 2
+  %mul1 = mul i32 %b1, %s
+; CHECK: [[BUMP:%[a-zA-Z0-9]+]] = shl i32 %s, 1
+; CHECK: %mul1 = add i32 %mul0, [[BUMP]]
+  call void @foo(i32 %mul1)
+
+  %b2 = add i32 %b, 4
+  %mul2 = mul i32 %b2, %s
+; CHECK: %mul2 = add i32 %mul1, [[BUMP]]
+  call void @foo(i32 %mul2)
+
+  ret void
+}
+
+; Do not rewrite a candidate if its potential basis does not dominate it.
+;
+; if (cond)
+;   foo(a * b);
+; foo((a + 1) * b);
+define void @not_dominate(i1 %cond, i32 %a, i32 %b) {
+; CHECK-LABEL: @not_dominate(
+entry:
+  %a1 = add i32 %a, 1
+  br i1 %cond, label %then, label %merge
+
+then:
+  %mul0 = mul i32 %a, %b
+; CHECK: %mul0 = mul i32 %a, %b
+  call void @foo(i32 %mul0)
+  br label %merge
+
+merge:
+  %mul1 = mul i32 %a1, %b
+; CHECK: %mul1 = mul i32 %a1, %b
+  call void @foo(i32 %mul1)
+  ret void
+}
+
+declare void @foo(i32)