llvm/test/CodeGen/ARM/gpr-paired-spill.ll
Tim Northover 4cc1407b84 ARM: Use ldrd/strd to spill 64-bit pairs when available.
This allows common sp-offsets to be part of the instruction and is
probably faster on modern CPUs too.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179977 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-21 11:57:07 +00:00

51 lines
2.5 KiB
LLVM

; RUN: llc -mtriple=armv7-none-linux-gnueabi -verify-machineinstrs < %s | FileCheck %s --check-prefix=CHECK-WITH-LDRD
; RUN: llc -mtriple=armv4-none-linux-gnueabi -verify-machineinstrs < %s | FileCheck %s --check-prefix=CHECK-WITHOUT-LDRD
; RUN: llc -mtriple=thumbv7-none-linux-gnueabi -verify-machineinstrs < %s | FileCheck %s --check-prefix=CHECK-WITH-LDRD
; RUN: llc -mtriple=thumbv7-none-linux-gnueabi -debug -o /dev/null < %s 2>&1 | FileCheck %s --check-prefix=INSTRS-ARE-THUMB
define void @foo(i64* %addr) {
%val1 = tail call i64 asm sideeffect "ldrexd $0, ${0:H}, [r0]", "=&r,r"(i64* %addr)
%val2 = tail call i64 asm sideeffect "ldrexd $0, ${0:H}, [r0]", "=&r,r"(i64* %addr)
%val3 = tail call i64 asm sideeffect "ldrexd $0, ${0:H}, [r0]", "=&r,r"(i64* %addr)
%val4 = tail call i64 asm sideeffect "ldrexd $0, ${0:H}, [r0]", "=&r,r"(i64* %addr)
%val5 = tail call i64 asm sideeffect "ldrexd $0, ${0:H}, [r0]", "=&r,r"(i64* %addr)
%val6 = tail call i64 asm sideeffect "ldrexd $0, ${0:H}, [r0]", "=&r,r"(i64* %addr)
%val7 = tail call i64 asm sideeffect "ldrexd $0, ${0:H}, [r0]", "=&r,r"(i64* %addr)
; Key point is that enough 64-bit paired GPR values are live that
; one of them has to be spilled. This used to cause an abort because
; an LDMIA was created with both a FrameIndex and an offset, which
; is not allowed.
; CHECK-WITH-LDRD: strd {{r[0-9]+}}, {{r[0-9]+}}, [sp, #8]
; CHECK-WITH-LDRD: strd {{r[0-9]+}}, {{r[0-9]+}}, [sp]
; CHECK-WITH-LDRD: ldrd {{r[0-9]+}}, {{r[0-9]+}}, [sp, #8]
; CHECK-WITH-LDRD: ldrd {{r[0-9]+}}, {{r[0-9]+}}, [sp]
; We also want to ensure the register scavenger is working (i.e. an
; offset from sp can be generated), so we need two spills.
; CHECK-WITHOUT-LDRD: add [[ADDRREG:[a-z0-9]+]], sp, #{{[0-9]+}}
; CHECK-WITHOUT-LDRD: stm [[ADDRREG]], {r{{[0-9]+}}, r{{[0-9]+}}}
; CHECK-WITHOUT-LDRD: stm sp, {r{{[0-9]+}}, r{{[0-9]+}}}
; In principle LLVM may have to recalculate the offset. At the moment
; it reuses the original though.
; CHECK-WITHOUT-LDRD: ldm [[ADDRREG]], {r{{[0-9]+}}, r{{[0-9]+}}}
; CHECK-WITHOUT-LDRD: ldm sp, {r{{[0-9]+}}, r{{[0-9]+}}}
; Make sure we are actually creating the Thumb versions of the spill
; instructions.
; INSTRS-ARE-THUMB: t2STRDi8
; INSTRS-ARE-THUMB: t2LDRDi8
store volatile i64 %val1, i64* %addr
store volatile i64 %val2, i64* %addr
store volatile i64 %val3, i64* %addr
store volatile i64 %val4, i64* %addr
store volatile i64 %val5, i64* %addr
store volatile i64 %val6, i64* %addr
store volatile i64 %val7, i64* %addr
ret void
}