[AArch64] add tests to show select transforms; NFC

llvm-svn: 288180

diff --git a/llvm/test/CodeGen/AArch64/selectcc-to-shiftand.ll b/llvm/test/CodeGen/AArch64/selectcc-to-shiftand.ll
new file mode 100644 (file)
index 0000000..6a288f4
--- /dev/null
+++ b/llvm/test/CodeGen/AArch64/selectcc-to-shiftand.ll
@@ -0,0 +1,133 @@
+; RUN: llc < %s -mtriple=aarch64-unknown-unknown | FileCheck %s
+
+; Compare if negative and select of constants where one constant is zero.
+
+define i32 @neg_sel_constants(i32 %a) {
+; CHECK-LABEL: neg_sel_constants:
+; CHECK:       // BB#0:
+; CHECK-NEXT:    mov w8, #5
+; CHECK-NEXT:    and w0, w8, w0, asr #31
+; CHECK-NEXT:    ret
+;
+  %tmp.1 = icmp slt i32 %a, 0
+  %retval = select i1 %tmp.1, i32 5, i32 0
+  ret i32 %retval
+}
+
+; Compare if negative and select of constants where one constant is zero and the other is a single bit.
+
+define i32 @neg_sel_special_constant(i32 %a) {
+; CHECK-LABEL: neg_sel_special_constant:
+; CHECK:       // BB#0:
+; CHECK-NEXT:    lsr w8, w0, #22
+; CHECK-NEXT:    and w0, w8, #0x200
+; CHECK-NEXT:    ret
+;
+  %tmp.1 = icmp slt i32 %a, 0
+  %retval = select i1 %tmp.1, i32 512, i32 0
+  ret i32 %retval
+}
+
+; Compare if negative and select variable or zero.
+
+define i32 @neg_sel_variable_and_zero(i32 %a, i32 %b) {
+; CHECK-LABEL: neg_sel_variable_and_zero:
+; CHECK:       // BB#0:
+; CHECK-NEXT:    and w0, w1, w0, asr #31
+; CHECK-NEXT:    ret
+;
+  %tmp.1 = icmp slt i32 %a, 0
+  %retval = select i1 %tmp.1, i32 %b, i32 0
+  ret i32 %retval
+}
+
+; Compare if not positive and select the same variable as being compared: smin(a, 0).
+
+define i32 @not_pos_sel_same_variable(i32 %a) {
+; CHECK-LABEL: not_pos_sel_same_variable:
+; CHECK:       // BB#0:
+; CHECK-NEXT:    and w0, w0, w0, asr #31
+; CHECK-NEXT:    ret
+;
+  %tmp = icmp slt i32 %a, 1
+  %min = select i1 %tmp, i32 %a, i32 0
+  ret i32 %min
+}
+
+; FIXME: Flipping the comparison condition can be handled by getting the bitwise not of the sign mask.
+
+; Compare if positive and select of constants where one constant is zero.
+
+define i32 @pos_sel_constants(i32 %a) {
+; CHECK-LABEL: pos_sel_constants:
+; CHECK:       // BB#0:
+; CHECK-NEXT:    cmp w0, #0
+; CHECK-NEXT:    mov w8, #5
+; CHECK-NEXT:    csel w0, w8, wzr, ge
+; CHECK-NEXT:    ret
+;
+  %tmp.1 = icmp sgt i32 %a, -1
+  %retval = select i1 %tmp.1, i32 5, i32 0
+  ret i32 %retval
+}
+
+; Compare if positive and select of constants where one constant is zero and the other is a single bit.
+
+define i32 @pos_sel_special_constant(i32 %a) {
+; CHECK-LABEL: pos_sel_special_constant:
+; CHECK:       // BB#0:
+; CHECK-NEXT:    cmp w0, #0
+; CHECK-NEXT:    cset w8, ge
+; CHECK-NEXT:    lsl w0, w8, #9
+; CHECK-NEXT:    ret
+;
+  %tmp.1 = icmp sgt i32 %a, -1
+  %retval = select i1 %tmp.1, i32 512, i32 0
+  ret i32 %retval
+}
+
+; Compare if positive and select variable or zero.
+
+define i32 @pos_sel_variable_and_zero(i32 %a, i32 %b) {
+; CHECK-LABEL: pos_sel_variable_and_zero:
+; CHECK:       // BB#0:
+; CHECK-NEXT:    cmp w0, #0
+; CHECK-NEXT:    csel w0, w1, wzr, ge
+; CHECK-NEXT:    ret
+;
+  %tmp.1 = icmp sgt i32 %a, -1
+  %retval = select i1 %tmp.1, i32 %b, i32 0
+  ret i32 %retval
+}
+
+; Compare if not negative or zero and select the same variable as being compared: smax(a, 0).
+
+define i32 @not_neg_sel_same_variable(i32 %a) {
+; CHECK-LABEL: not_neg_sel_same_variable:
+; CHECK:       // BB#0:
+; CHECK-NEXT:    cmp w0, #0
+; CHECK-NEXT:    csel w0, w0, wzr, gt
+; CHECK-NEXT:    ret
+;
+  %tmp = icmp sgt i32 %a, 0
+  %min = select i1 %tmp, i32 %a, i32 0
+  ret i32 %min
+}
+
+; https://llvm.org/bugs/show_bug.cgi?id=31175
+
+; ret = (x-y) > 0 ? x-y : 0
+define i32 @PR31175(i32 %x, i32 %y) {
+; CHECK-LABEL: PR31175:
+; CHECK:       // BB#0:
+; CHECK-NEXT:    sub w8, w0, w1
+; CHECK-NEXT:    cmp w8, #0
+; CHECK-NEXT:    csel w0, w8, wzr, gt
+; CHECK-NEXT:    ret
+;
+  %sub = sub nsw i32 %x, %y
+  %cmp = icmp sgt i32 %sub, 0
+  %sel = select i1 %cmp, i32 %sub, i32 0
+  ret i32 %sel
+}
+