# RUN: llc -run-pass=prologepilog -reverse-csr-restore-seq -o - -mtriple=aarch64-- %s | FileCheck %s --check-prefixes=CHECK # RUN: llc -start-before=prologepilog -stop-after=aarch64-ldst-opt -reverse-csr-restore-seq -o - -mtriple=aarch64-- %s | FileCheck %s --check-prefixes=CHECK # --- | define void @foo() nounwind { entry: unreachable } define void @bar() nounwind { entry: unreachable } define void @baz() nounwind { entry: unreachable } ... --- name: foo # CHECK-LABEL: name: foo tracksRegLiveness: true body: | bb.0: $x19 = IMPLICIT_DEF $x20 = IMPLICIT_DEF $x21 = IMPLICIT_DEF $x22 = IMPLICIT_DEF $x23 = IMPLICIT_DEF $x24 = IMPLICIT_DEF $x25 = IMPLICIT_DEF $x26 = IMPLICIT_DEF ; The local stack size is 0, so the last ldp in the sequence will also ; restore the stack. ; CHECK: $x24, $x23 = frame-destroy LDPXi $sp, 2 ; CHECK-NEXT: $x22, $x21 = frame-destroy LDPXi $sp, 4 ; CHECK-NEXT: $x20, $x19 = frame-destroy LDPXi $sp, 6 ; The ldp and the stack increment get merged even before ; the load-store optimizer. ; CHECK-NEXT: early-clobber $sp, $x26, $x25 = frame-destroy LDPXpost $sp, 8 RET_ReallyLR ... --- name: bar # CHECK-LABEL: name: bar tracksRegLiveness: true stack: - { id : 0, size: 8, alignment: 4, stack-id: default, callee-saved-register: '', callee-saved-restored: true, local-offset: -4, debug-info-variable: '', debug-info-expression: '', debug-info-location: '' } body: | bb.0: $x19 = IMPLICIT_DEF $x20 = IMPLICIT_DEF $x21 = IMPLICIT_DEF $x22 = IMPLICIT_DEF $x23 = IMPLICIT_DEF $x24 = IMPLICIT_DEF $x25 = IMPLICIT_DEF $x26 = IMPLICIT_DEF ; The local stack size is not 0, and we can combine the CSR stack size with ; the local stack size. This results in rewriting the offsets for all the ; save/restores and forbids us to merge the stack adjustment and the last pop. ; In this case, there is no point of moving the first CSR pair at the end. ; We do it anyway, as it's a small price to pay for the resulting ; simplification in the epilogue emission code. ; CHECK: $x24, $x23 = frame-destroy LDPXi $sp, 4 ; CHECK-NEXT: $x22, $x21 = frame-destroy LDPXi $sp, 6 ; CHECK-NEXT: $x20, $x19 = frame-destroy LDPXi $sp, 8 ; CHECK-NEXT: $x26, $x25 = frame-destroy LDPXi $sp, 2 ; CHECK-NEXT: $sp = frame-destroy ADDXri $sp, 80, 0 RET_ReallyLR ... --- # Check that the load from the offset 0 is moved at the end even when hasFP is # false. name: baz # CHECK-LABEL: name: baz alignment: 4 tracksRegLiveness: true frameInfo: adjustsStack: true hasCalls: true body: | bb.0: successors: %bb.1 $x0 = IMPLICIT_DEF $x20 = IMPLICIT_DEF $x21 = IMPLICIT_DEF ADJCALLSTACKDOWN 0, 0, implicit-def dead $sp, implicit $sp BL @foo, csr_aarch64_aapcs, implicit-def dead $lr, implicit $sp, implicit $x0, implicit-def $sp, implicit-def $x0 ADJCALLSTACKUP 0, 0, implicit-def dead $sp, implicit $sp B %bb.1 bb.1: ; CHECK: $x21, $x20 = frame-destroy LDPXi $sp, 2 ; CHECK-NEXT: early-clobber $sp, $lr = frame-destroy LDRXpost $sp, 32 RET_ReallyLR ...