| ; 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 | |
| } | |
| ; 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: mov w8, #5 | |
| ; CHECK-NEXT: bic w0, w8, w0, asr #31 | |
| ; 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: orr w8, wzr, #0x200 | |
| ; CHECK-NEXT: bic w0, w8, w0, lsr #22 | |
| ; 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: bic w0, w1, w0, asr #31 | |
| ; 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: bic w0, w0, w0, asr #31 | |
| ; 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: bic w0, w8, w8, asr #31 | |
| ; 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 | |
| } | |