1# Check that we can remove the redundant save of constant registers such as $zero 2# RUN: llc -mtriple=mips64-unknown-freebsd %s -start-before=machine-cp -o - | FileCheck %s --check-prefix ASM 3# RUN: llc -mtriple=mips64-unknown-freebsd %s -verify-machineinstrs -run-pass=machine-cp -o - | FileCheck %s 4--- | 5 target triple = "mips64-unknown-freebsd" 6 define i32 @a() nounwind { 7 ; ASM-LABEL: a: 8 ; ASM: # %bb.0: 9 ; ASM-NEXT: daddiu $sp, $sp, -16 10 ; ASM-NEXT: sd $ra, 8($sp) # 8-byte Folded Spill 11 ; ASM-NEXT: jalr $25 12 ; ASM-NEXT: move $4, $zero 13 ; ASM-NEXT: move $4, $zero 14 ; ASM-NEXT: ld $ra, 8($sp) # 8-byte Folded Reload 15 ; ASM-NEXT: jr $ra 16 ; ASM-NEXT: daddiu $sp, $sp, 16 17 ret i32 0 18 } 19... 20--- 21name: a 22frameInfo: 23 adjustsStack: true 24body: | 25 bb.0 (%ir-block.0): 26 liveins: $a0_64, $t9_64, $ra_64, $fp_64, $gp_64 27 ; CHECK-LABEL: name: a 28 ; CHECK: liveins: $a0_64, $t9_64, $ra_64, $fp_64, $gp_64 29 ; CHECK-NEXT: {{ $}} 30 ; CHECK-NEXT: ADJCALLSTACKDOWN 0, 0, implicit-def dead $sp, implicit $sp 31 ; CHECK-NEXT: $a0_64 = COPY $zero_64 32 ; CHECK-NEXT: JALR64Pseudo $t9_64, csr_n64, implicit-def dead $ra, implicit $a0_64, implicit $gp_64, implicit-def $sp, implicit-def $v0 33 ; CHECK-NEXT: ADJCALLSTACKUP 0, 0, implicit-def dead $sp, implicit $sp 34 ; CHECK-NEXT: $a0_64 = COPY $zero_64 35 ; CHECK-NEXT: PseudoReturn64 undef $ra_64, implicit $v0_64, implicit killed $a0_64 36 ADJCALLSTACKDOWN 0, 0, implicit-def dead $sp, implicit $sp 37 renamable $s0_64 = COPY $zero_64 38 $a0_64 = COPY renamable $s0_64 39 JALR64Pseudo $t9_64, csr_n64, implicit-def dead $ra, implicit $a0_64, implicit $gp_64, implicit-def $sp, implicit-def $v0 40 ADJCALLSTACKUP 0, 0, implicit-def dead $sp, implicit $sp 41 $a0_64 = COPY killed renamable $s0_64 42 PseudoReturn64 undef $ra_64, implicit $v0_64, implicit killed $a0_64 43... 44