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llvm-project/llvm/test/CodeGen/Thumb/copy_thumb.ll

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Lower thumbv4t & thumbv5 lo->lo copies through a push-pop sequence On pre-v6 hardware, 'MOV lo, lo' gives undefined results, so such copies need to be avoided. This patch trades simplicity for implementation time at the expense of performance... As they say: correctness first, then performance. See http://lists.cs.uiuc.edu/pipermail/llvmdev/2014-August/075998.html for a few ideas on how to make this better. llvm-svn: 216138
2014-08-21 07:38:50 +08:00
; RUN: llc -mtriple=armv4-none--eabi < %s | FileCheck %s --check-prefix=CHECK-LOLOMOV
; RUN: llc -mtriple=armv4t-none--eabi < %s | FileCheck %s --check-prefix=CHECK-LOLOMOV
; RUN: llc -mtriple=armv5-none--eabi < %s | FileCheck %s --check-prefix=CHECK-LOLOMOV
; RUN: llc -mtriple=armv6-none--eabi < %s | FileCheck %s --check-prefix=CHECK-LOLOMOV
; RUN: llc -mtriple=armv7-none--eabi < %s | FileCheck %s --check-prefix=CHECK-LOLOMOV
; RUN: llc -mtriple=thumbv6-none--eabi < %s | FileCheck %s --check-prefix=CHECK-LOLOMOV
; RUN: llc -mtriple=thumbv7-none--eabi < %s | FileCheck %s --check-prefix=CHECK-LOLOMOV
; CHECK-LOLOMOV-LABEL: foo
; CHECK-LOLOMOV: mov [[TMP:r[0-7]]], [[SRC1:r[01]]]
; CHECK-LOLOMOV-NEXT: mov [[SRC1]], [[SRC2:r[01]]]
; CHECK-LOLOMOV-NEXT: mov [[SRC2]], [[TMP]]
; CHECK-LOLOMOV-LABEL: bar
; CHECK-LOLOMOV-LABEL: fnend
;
; 'MOV lo, lo' in Thumb mode produces undefined results on pre-v6 hardware
; RUN: llc -mtriple=thumbv4t-none--eabi < %s | FileCheck %s --check-prefix=CHECK-NOLOLOMOV
; RUN: llc -mtriple=thumbv5-none--eabi < %s | FileCheck %s --check-prefix=CHECK-NOLOLOMOV
; CHECK-NOLOLOMOV-LABEL: foo
; CHECK-NOLOLOMOV-NOT: mov [[TMP:r[0-7]]], [[SRC1:r[01]]]
; CHECK-NOLOLOMOV: push {[[SRC1:r[01]]]}
; CHECK-NOLOLOMOV-NEXT: pop {[[TMP:r[0-7]]]}
; CHECK-NOLOLOMOV-NOT: mov [[TMP:r[0-7]]], [[SRC1:r[01]]]
; CHECK-NOLOLOMOV: push {[[SRC2:r[01]]]}
; CHECK-NOLOLOMOV-NEXT: pop {[[SRC1]]}
; CHECK-NOLOLOMOV-NOT: mov [[TMP:r[0-7]]], [[SRC1:r[01]]]
; CHECK-NOLOLOMOV: push {[[TMP]]}
; CHECK-NOLOLOMOV-NEXT: pop {[[SRC2]]}
; CHECK-NOLOLOMOV-LABEL: bar
; CHECK-NOLOLOMOV-LABEL: fnend
declare void @bar(i32, i32)
define void @foo(i32 %a, i32 %b) {
entry:
call void @bar(i32 %b, i32 %a);
ret void
}