llvm/test/CodeGen/PowerPC/subtract_from_imm.ll
Nemanja Ivanovic ab05c2009d [PowerPC] Use subfic instruction for subtract from immediate
Provide a 64-bit pattern to use SUBFIC for subtracting from a 16-bit immediate.
The corresponding pattern already exists for 32-bit integers.

Committing on behalf of Hiroshi Inoue.

Differential Revision: https://reviews.llvm.org/D29387


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296144 91177308-0d34-0410-b5e6-96231b3b80d8
2017-02-24 18:16:06 +00:00

42 lines
969 B
LLVM

; RUN: llc -verify-machineinstrs -mtriple=powerpc64le-unknown-linux-gnu < %s | FileCheck %s
; RUN: llc -verify-machineinstrs -mtriple=powerpc64-unknown-linux-gnu < %s | FileCheck %s
; Make sure that the subfic is generated iff possible
define i64 @subtract_from_imm1(i64 %v) nounwind readnone {
entry:
; CHECK-LABEL: subtract_from_imm1
; CHECK: subfic 3, 3, 32767
; CHECK: blr
%sub = sub i64 32767, %v
ret i64 %sub
}
define i64 @subtract_from_imm2(i64 %v) nounwind readnone {
entry:
; CHECK-LABEL: subtract_from_imm2
; CHECK-NOT: subfic
; CHECK: blr
%sub = sub i64 32768, %v
ret i64 %sub
}
define i64 @subtract_from_imm3(i64 %v) nounwind readnone {
entry:
; CHECK-LABEL: subtract_from_imm3
; CHECK: subfic 3, 3, -32768
; CHECK: blr
%sub = sub i64 -32768, %v
ret i64 %sub
}
define i64 @subtract_from_imm4(i64 %v) nounwind readnone {
entry:
; CHECK-LABEL: subtract_from_imm4
; CHECK-NOT: subfic
; CHECK: blr
%sub = sub i64 -32769, %v
ret i64 %sub
}