; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py ; RUN: llc < %s -mtriple=arm-eabi-unknown-unknown | FileCheck %s ; Select of constants: control flow / conditional moves can always be replaced by logic+math (but may not be worth it?). ; Test the zeroext/signext variants of each pattern to see if that makes a difference. ; select Cond, 0, 1 --> zext (!Cond) define i32 @select_0_or_1(i1 %cond) { ; CHECK-LABEL: select_0_or_1: ; CHECK: @ %bb.0: ; CHECK-NEXT: mov r1, #1 ; CHECK-NEXT: bic r0, r1, r0 ; CHECK-NEXT: mov pc, lr %sel = select i1 %cond, i32 0, i32 1 ret i32 %sel } define i32 @select_0_or_1_zeroext(i1 zeroext %cond) { ; CHECK-LABEL: select_0_or_1_zeroext: ; CHECK: @ %bb.0: ; CHECK-NEXT: eor r0, r0, #1 ; CHECK-NEXT: mov pc, lr %sel = select i1 %cond, i32 0, i32 1 ret i32 %sel } define i32 @select_0_or_1_signext(i1 signext %cond) { ; CHECK-LABEL: select_0_or_1_signext: ; CHECK: @ %bb.0: ; CHECK-NEXT: mov r1, #1 ; CHECK-NEXT: bic r0, r1, r0 ; CHECK-NEXT: mov pc, lr %sel = select i1 %cond, i32 0, i32 1 ret i32 %sel } ; select Cond, 1, 0 --> zext (Cond) define i32 @select_1_or_0(i1 %cond) { ; CHECK-LABEL: select_1_or_0: ; CHECK: @ %bb.0: ; CHECK-NEXT: and r0, r0, #1 ; CHECK-NEXT: mov pc, lr %sel = select i1 %cond, i32 1, i32 0 ret i32 %sel } define i32 @select_1_or_0_zeroext(i1 zeroext %cond) { ; CHECK-LABEL: select_1_or_0_zeroext: ; CHECK: @ %bb.0: ; CHECK-NEXT: mov pc, lr %sel = select i1 %cond, i32 1, i32 0 ret i32 %sel } define i32 @select_1_or_0_signext(i1 signext %cond) { ; CHECK-LABEL: select_1_or_0_signext: ; CHECK: @ %bb.0: ; CHECK-NEXT: and r0, r0, #1 ; CHECK-NEXT: mov pc, lr %sel = select i1 %cond, i32 1, i32 0 ret i32 %sel } ; select Cond, 0, -1 --> sext (!Cond) define i32 @select_0_or_neg1(i1 %cond) { ; CHECK-LABEL: select_0_or_neg1: ; CHECK: @ %bb.0: ; CHECK-NEXT: mov r1, #1 ; CHECK-NEXT: bic r0, r1, r0 ; CHECK-NEXT: rsb r0, r0, #0 ; CHECK-NEXT: mov pc, lr %sel = select i1 %cond, i32 0, i32 -1 ret i32 %sel } define i32 @select_0_or_neg1_zeroext(i1 zeroext %cond) { ; CHECK-LABEL: select_0_or_neg1_zeroext: ; CHECK: @ %bb.0: ; CHECK-NEXT: eor r0, r0, #1 ; CHECK-NEXT: rsb r0, r0, #0 ; CHECK-NEXT: mov pc, lr %sel = select i1 %cond, i32 0, i32 -1 ret i32 %sel } define i32 @select_0_or_neg1_signext(i1 signext %cond) { ; CHECK-LABEL: select_0_or_neg1_signext: ; CHECK: @ %bb.0: ; CHECK-NEXT: mvn r0, r0 ; CHECK-NEXT: mov pc, lr %sel = select i1 %cond, i32 0, i32 -1 ret i32 %sel } define i32 @select_0_or_neg1_alt(i1 %cond) { ; CHECK-LABEL: select_0_or_neg1_alt: ; CHECK: @ %bb.0: ; CHECK-NEXT: and r0, r0, #1 ; CHECK-NEXT: sub r0, r0, #1 ; CHECK-NEXT: mov pc, lr %z = zext i1 %cond to i32 %add = add i32 %z, -1 ret i32 %add } define i32 @select_0_or_neg1_alt_zeroext(i1 zeroext %cond) { ; CHECK-LABEL: select_0_or_neg1_alt_zeroext: ; CHECK: @ %bb.0: ; CHECK-NEXT: sub r0, r0, #1 ; CHECK-NEXT: mov pc, lr %z = zext i1 %cond to i32 %add = add i32 %z, -1 ret i32 %add } define i32 @select_0_or_neg1_alt_signext(i1 signext %cond) { ; CHECK-LABEL: select_0_or_neg1_alt_signext: ; CHECK: @ %bb.0: ; CHECK-NEXT: mvn r0, r0 ; CHECK-NEXT: mov pc, lr %z = zext i1 %cond to i32 %add = add i32 %z, -1 ret i32 %add } ; select Cond, -1, 0 --> sext (Cond) define i32 @select_neg1_or_0(i1 %cond) { ; CHECK-LABEL: select_neg1_or_0: ; CHECK: @ %bb.0: ; CHECK-NEXT: and r0, r0, #1 ; CHECK-NEXT: rsb r0, r0, #0 ; CHECK-NEXT: mov pc, lr %sel = select i1 %cond, i32 -1, i32 0 ret i32 %sel } define i32 @select_neg1_or_0_zeroext(i1 zeroext %cond) { ; CHECK-LABEL: select_neg1_or_0_zeroext: ; CHECK: @ %bb.0: ; CHECK-NEXT: rsb r0, r0, #0 ; CHECK-NEXT: mov pc, lr %sel = select i1 %cond, i32 -1, i32 0 ret i32 %sel } define i32 @select_neg1_or_0_signext(i1 signext %cond) { ; CHECK-LABEL: select_neg1_or_0_signext: ; CHECK: @ %bb.0: ; CHECK-NEXT: mov pc, lr %sel = select i1 %cond, i32 -1, i32 0 ret i32 %sel } ; select Cond, C+1, C --> add (zext Cond), C define i32 @select_Cplus1_C(i1 %cond) { ; CHECK-LABEL: select_Cplus1_C: ; CHECK: @ %bb.0: ; CHECK-NEXT: mov r1, #41 ; CHECK-NEXT: tst r0, #1 ; CHECK-NEXT: movne r1, #42 ; CHECK-NEXT: mov r0, r1 ; CHECK-NEXT: mov pc, lr %sel = select i1 %cond, i32 42, i32 41 ret i32 %sel } define i32 @select_Cplus1_C_zeroext(i1 zeroext %cond) { ; CHECK-LABEL: select_Cplus1_C_zeroext: ; CHECK: @ %bb.0: ; CHECK-NEXT: mov r1, #41 ; CHECK-NEXT: cmp r0, #0 ; CHECK-NEXT: movne r1, #42 ; CHECK-NEXT: mov r0, r1 ; CHECK-NEXT: mov pc, lr %sel = select i1 %cond, i32 42, i32 41 ret i32 %sel } define i32 @select_Cplus1_C_signext(i1 signext %cond) { ; CHECK-LABEL: select_Cplus1_C_signext: ; CHECK: @ %bb.0: ; CHECK-NEXT: mov r1, #41 ; CHECK-NEXT: tst r0, #1 ; CHECK-NEXT: movne r1, #42 ; CHECK-NEXT: mov r0, r1 ; CHECK-NEXT: mov pc, lr %sel = select i1 %cond, i32 42, i32 41 ret i32 %sel } ; select Cond, C, C+1 --> add (sext Cond), C define i32 @select_C_Cplus1(i1 %cond) { ; CHECK-LABEL: select_C_Cplus1: ; CHECK: @ %bb.0: ; CHECK-NEXT: mov r1, #42 ; CHECK-NEXT: tst r0, #1 ; CHECK-NEXT: movne r1, #41 ; CHECK-NEXT: mov r0, r1 ; CHECK-NEXT: mov pc, lr %sel = select i1 %cond, i32 41, i32 42 ret i32 %sel } define i32 @select_C_Cplus1_zeroext(i1 zeroext %cond) { ; CHECK-LABEL: select_C_Cplus1_zeroext: ; CHECK: @ %bb.0: ; CHECK-NEXT: mov r1, #42 ; CHECK-NEXT: cmp r0, #0 ; CHECK-NEXT: movne r1, #41 ; CHECK-NEXT: mov r0, r1 ; CHECK-NEXT: mov pc, lr %sel = select i1 %cond, i32 41, i32 42 ret i32 %sel } define i32 @select_C_Cplus1_signext(i1 signext %cond) { ; CHECK-LABEL: select_C_Cplus1_signext: ; CHECK: @ %bb.0: ; CHECK-NEXT: mov r1, #42 ; CHECK-NEXT: tst r0, #1 ; CHECK-NEXT: movne r1, #41 ; CHECK-NEXT: mov r0, r1 ; CHECK-NEXT: mov pc, lr %sel = select i1 %cond, i32 41, i32 42 ret i32 %sel } ; In general, select of 2 constants could be: ; select Cond, C1, C2 --> add (mul (zext Cond), C1-C2), C2 --> add (and (sext Cond), C1-C2), C2 define i32 @select_C1_C2(i1 %cond) { ; CHECK-LABEL: select_C1_C2: ; CHECK: @ %bb.0: ; CHECK-NEXT: mov r1, #165 ; CHECK-NEXT: tst r0, #1 ; CHECK-NEXT: orr r1, r1, #256 ; CHECK-NEXT: moveq r1, #42 ; CHECK-NEXT: mov r0, r1 ; CHECK-NEXT: mov pc, lr %sel = select i1 %cond, i32 421, i32 42 ret i32 %sel } define i32 @select_C1_C2_zeroext(i1 zeroext %cond) { ; CHECK-LABEL: select_C1_C2_zeroext: ; CHECK: @ %bb.0: ; CHECK-NEXT: mov r1, #165 ; CHECK-NEXT: cmp r0, #0 ; CHECK-NEXT: orr r1, r1, #256 ; CHECK-NEXT: moveq r1, #42 ; CHECK-NEXT: mov r0, r1 ; CHECK-NEXT: mov pc, lr %sel = select i1 %cond, i32 421, i32 42 ret i32 %sel } define i32 @select_C1_C2_signext(i1 signext %cond) { ; CHECK-LABEL: select_C1_C2_signext: ; CHECK: @ %bb.0: ; CHECK-NEXT: mov r1, #165 ; CHECK-NEXT: tst r0, #1 ; CHECK-NEXT: orr r1, r1, #256 ; CHECK-NEXT: moveq r1, #42 ; CHECK-NEXT: mov r0, r1 ; CHECK-NEXT: mov pc, lr %sel = select i1 %cond, i32 421, i32 42 ret i32 %sel } ; 4295032833 = 0x100010001. ; This becomes an opaque constant via ConstantHoisting, so we don't fold it into the select. define i64 @opaque_constant1(i1 %cond, i64 %x) { ; CHECK-LABEL: opaque_constant1: ; CHECK: @ %bb.0: ; CHECK-NEXT: .save {r4, lr} ; CHECK-NEXT: push {r4, lr} ; CHECK-NEXT: mov lr, #1 ; CHECK-NEXT: ands r12, r0, #1 ; CHECK-NEXT: mov r0, #23 ; CHECK-NEXT: orr lr, lr, #65536 ; CHECK-NEXT: mvnne r0, #3 ; CHECK-NEXT: and r4, r0, lr ; CHECK-NEXT: movne r12, #1 ; CHECK-NEXT: subs r0, r4, #1 ; CHECK-NEXT: eor r2, r2, lr ; CHECK-NEXT: eor r3, r3, #1 ; CHECK-NEXT: sbc r1, r12, #0 ; CHECK-NEXT: orrs r2, r2, r3 ; CHECK-NEXT: movne r0, r4 ; CHECK-NEXT: movne r1, r12 ; CHECK-NEXT: pop {r4, lr} ; CHECK-NEXT: mov pc, lr %sel = select i1 %cond, i64 -4, i64 23 %bo = and i64 %sel, 4295032833 ; 0x100010001 %cmp = icmp eq i64 %x, 4295032833 %sext = sext i1 %cmp to i64 %add = add i64 %bo, %sext ret i64 %add } ; 65537 == 0x10001. ; This becomes an opaque constant via ConstantHoisting, so we don't fold it into the select. define i64 @opaque_constant2(i1 %cond, i64 %x) { ; CHECK-LABEL: opaque_constant2: ; CHECK: @ %bb.0: ; CHECK-NEXT: mov r1, #1 ; CHECK-NEXT: tst r0, #1 ; CHECK-NEXT: orr r1, r1, #65536 ; CHECK-NEXT: moveq r1, #23 ; CHECK-NEXT: bic r0, r1, #22 ; CHECK-NEXT: mov r1, #0 ; CHECK-NEXT: mov pc, lr %sel = select i1 %cond, i64 65537, i64 23 %bo = and i64 %sel, 65537 ret i64 %bo }