[ARM] Honour ABI for rem under -O0 for EABI, GNUEABI, Android and Musl

At higher optimization levels, we generate the libcall for DIVREM_Ix, which is
fine: aeabi_{u|i}divmod. At -O0 we generate the one for REM_Ix, which is the
default {u}mod{q|h|s|d}i3.

This commit makes sure that we don't generate REM_Ix calls for ABIs that
don't support them (i.e. where we need to use DIVREM_Ix instead). This is
achieved by bailing out of FastISel, which can't handle non-double multi-reg
returns, and letting the legalization infrastructure expand the REM_Ix calls.

It also updates the divmod-eabi.ll test to run under -O0 as well, and adds some
Windows checks to it to make sure we don't break things for it.

Fixes PR27068

Differential Revision: https://reviews.llvm.org/D21926

llvm-svn: 275773
This commit is contained in:
Diana Picus 2016-07-18 06:48:25 +00:00
parent 197228927a
commit 774d157a5d
5 changed files with 124 additions and 12 deletions

View File

@ -238,6 +238,11 @@ public:
return false;
}
/// Return true if the target can handle a standalone remainder operation.
virtual bool hasStandaloneRem(EVT VT) const {
return true;
}
/// Return true if sqrt(x) is as cheap or cheaper than 1 / rsqrt(x)
bool isFsqrtCheap() const {
return FsqrtIsCheap;

View File

@ -1718,6 +1718,13 @@ bool ARMFastISel::SelectRem(const Instruction *I, bool isSigned) {
if (!isTypeLegal(Ty, VT))
return false;
// Many ABIs do not provide a libcall for standalone remainder, so we need to
// use divrem (see the RTABI 4.3.1). Since FastISel can't handle non-double
// multi-reg returns, we'll have to bail out.
if (!TLI.hasStandaloneRem(VT)) {
return false;
}
RTLIB::Libcall LC = RTLIB::UNKNOWN_LIBCALL;
if (VT == MVT::i8)
LC = isSigned ? RTLIB::SREM_I8 : RTLIB::UREM_I8;

View File

@ -806,6 +806,7 @@ ARMTargetLowering::ARMTargetLowering(const TargetMachine &TM,
Subtarget->isTargetGNUAEABI() || Subtarget->isTargetMuslAEABI()) {
setOperationAction(ISD::SREM, MVT::i64, Custom);
setOperationAction(ISD::UREM, MVT::i64, Custom);
HasStandaloneRem = false;
setLibcallName(RTLIB::SDIVREM_I8, "__aeabi_idivmod");
setLibcallName(RTLIB::SDIVREM_I16, "__aeabi_idivmod");

View File

@ -478,6 +478,10 @@ namespace llvm {
return true;
}
bool hasStandaloneRem(EVT VT) const override {
return HasStandaloneRem;
}
protected:
std::pair<const TargetRegisterClass *, uint8_t>
findRepresentativeClass(const TargetRegisterInfo *TRI,
@ -500,6 +504,8 @@ namespace llvm {
// check.
bool InsertFencesForAtomic;
bool HasStandaloneRem = true;
void addTypeForNEON(MVT VT, MVT PromotedLdStVT, MVT PromotedBitwiseVT);
void addDRTypeForNEON(MVT VT);
void addQRTypeForNEON(MVT VT);

View File

@ -1,16 +1,33 @@
; We run the tests with both the default optimization level and O0, to make sure
; we don't have any ABI differences between them. In principle, the ABI checks
; should be the same for both optimization levels (there could be exceptions
; from this when a div and a mod with the same operands are not coallesced into
; the same divmod, but luckily this doesn't occur in practice even at O0).
; Sometimes the checks that the correct registers are used after the libcalls
; are different between optimization levels, so we have to separate them.
; RUN: llc -mtriple armv7-none-eabi %s -o - | FileCheck %s --check-prefix=EABI
; RUN: llc -mtriple armv7-none-eabi %s -o - -O0 -optimize-regalloc | FileCheck %s --check-prefix=EABI
; RUN: llc -mtriple armv7-none-eabihf %s -o - | FileCheck %s --check-prefix=EABI
; RUN: llc -mtriple armv7-none-eabihf %s -o - -O0 -optimize-regalloc | FileCheck %s --check-prefix=EABI
; All "eabi" (Bare, GNU and Android) must lower SREM/UREM to __aeabi_{u,i}divmod
; RUN: llc -mtriple armv7-linux-androideabi %s -o - | FileCheck %s --check-prefix=EABI
; RUN: llc -mtriple armv7-linux-androideabi %s -o - -O0 -optimize-regalloc | FileCheck %s --check-prefix=EABI
; RUN: llc -mtriple armv7-linux-gnueabi %s -o - | FileCheck %s --check-prefix=EABI
; RUN: llc -mtriple armv7-linux-gnueabi %s -o - -O0 -optimize-regalloc | FileCheck %s --check-prefix=EABI
; RUN: llc -mtriple armv7-linux-musleabi %s -o - | FileCheck %s --check-prefix=EABI
; RUN: llc -mtriple armv7-apple-darwin %s -o - | FileCheck %s --check-prefix=DARWIN
; RUN: llc -mtriple armv7-linux-musleabi %s -o - -O0 -optimize-regalloc | FileCheck %s --check-prefix=EABI
; RUN: llc -mtriple armv7-apple-darwin %s -o - | FileCheck %s --check-prefixes=DARWIN,DARWIN-DEFAULT
; RUN: llc -mtriple armv7-apple-darwin %s -o - -O0 -optimize-regalloc | FileCheck %s --check-prefixes=DARWIN,DARWIN-O0
; FIXME: long-term, we will use "-apple-macho" and won't need this exception:
; RUN: llc -mtriple armv7-apple-darwin-eabi %s -o - | FileCheck %s --check-prefix=DARWIN
; RUN: llc -mtriple armv7-apple-darwin-eabi %s -o - | FileCheck %s --check-prefixes=DARWIN,DARWIN-DEFAULT
; RUN: llc -mtriple armv7-apple-darwin-eabi %s -o - -O0 -optimize-regalloc | FileCheck %s --check-prefixes=DARWIN,DARWIN-O0
; RUN: llc -mtriple thumbv7-windows %s -o - | FileCheck %s --check-prefixes=WINDOWS,WINDOWS-DEFAULT
; RUN: llc -mtriple thumbv7-windows %s -o - -O0 -optimize-regalloc | FileCheck %s --check-prefixes=WINDOWS,WINDOWS-O0
define signext i16 @f16(i16 signext %a, i16 signext %b) {
; EABI-LABEL: f16:
; DARWIN-LABEL: f16:
; WINDOWS-LABEL: f16:
entry:
%conv = sext i16 %a to i32
%conv1 = sext i16 %b to i32
@ -20,25 +37,39 @@ entry:
; EABI: mov [[div:r[0-9]+]], r0
; EABI: mov [[rem:r[0-9]+]], r1
; DARWIN: ___divsi3
; DARWIN: mov [[sum:r[0-9]+]], r0
; DARWIN: mov [[div:r[0-9]+]], r0
; DARWIN: __modsi3
; DARWIN: add [[sum]]{{.*}}r0
; DARWIN-DEFAULT: add [[sum:r[0-9]+]], r0, [[div]]
; DARWIN-O0: mov [[rem:r[0-9]+]], r0
; WINDOWS: __rt_sdiv
; WINDOWS-DEFAULT: mls [[rem:r[0-9]+]], r0,
; WINDOWS-DEFAULT: adds [[sum:r[0-9]+]], [[rem]], r0
; WINDOWS-O0: mov [[div:r[0-9]+]], r0
; WINDOWS-O0: mls [[rem:r[0-9]+]], [[div]],
%rem8 = srem i32 %conv1, %conv
; EABI: __aeabi_idivmod
; DARWIN: __modsi3
; WINDOWS: __rt_sdiv
; WINDOWS: mls [[rem1:r[0-9]+]], r0,
%add = add nsw i32 %rem, %div
%add13 = add nsw i32 %add, %rem8
%conv14 = trunc i32 %add13 to i16
; EABI: add r0{{.*}}r1
; EABI: sxth r0, r0
; DARWIN: add r0{{.*}}[[sum]]
; DARWIN: sxth r0, r0
; DARWIN-DEFAULT: add [[res:r[0-9]+]], [[sum]], r0
; DARWIN-O0: add [[sum:r[0-9]+]], [[rem]], [[div]]
; DARWIN-O0: add [[res:r[0-9]+]], [[sum]], r0
; DARWIN: sxth r0, [[res]]
; WINDOWS-O0: adds [[sum:r[0-9]+]], [[rem]], [[div]]
; WINDOWS: add [[rem1]], [[sum]]
; WINDOWS: sxth [[res:r[0-9]+]], [[rem1]]
ret i16 %conv14
}
define i32 @f32(i32 %a, i32 %b) {
; EABI-LABEL: f32:
; DARWIN-LABEL: f32:
; WINDOWS-LABEL: f32:
entry:
%div = sdiv i32 %a, %b
%rem = srem i32 %a, %b
@ -46,43 +77,71 @@ entry:
; EABI: mov [[div:r[0-9]+]], r0
; EABI: mov [[rem:r[0-9]+]], r1
; DARWIN: ___divsi3
; DARWIN: mov [[sum:r[0-9]+]], r0
; DARWIN: mov [[div:r[0-9]+]], r0
; DARWIN: __modsi3
; DARWIN: add [[sum]]{{.*}}r0
; DARWIN-DEFAULT: add [[sum:r[0-9]+]], r0, [[div]]
; DARWIN-O0: mov [[rem:r[0-9]+]], r0
; WINDOWS: __rt_sdiv
; WINDOWS: mov [[div:r[0-9]+]], r0
; WINDOWS: __rt_sdiv
; WINDOWS: mls [[rem:r[0-9]+]], r0,
; WINDOWS-DEFAULT: add [[div]], [[rem]]
%rem1 = srem i32 %b, %a
; EABI: __aeabi_idivmod
; DARWIN: __modsi3
; WINDOWS: __rt_sdiv
; WINDOWS: mls [[rem1:r[0-9]+]], r0,
%add = add nsw i32 %rem, %div
%add2 = add nsw i32 %add, %rem1
; EABI: add r0{{.*}}r1
; DARWIN: add r0{{.*}}[[sum]]
; DARWIN-DEFAULT: add r0, [[sum]], r0
; DARWIN-O0: add [[sum:r[0-9]+]], [[rem]], [[div]]
; DARWIN-O0: add [[res:r[0-9]+]], [[sum]], r0
; WINDOWS-DEFAULT: add [[rem1]], [[div]]
; WINDOWS-O0: adds [[sum:r[0-9]+]], [[rem]], [[div]]
; WINDOWS-O0: add [[rem1]], [[sum]]
ret i32 %add2
}
define i32 @uf(i32 %a, i32 %b) {
; EABI-LABEL: uf:
; DARWIN-LABEL: uf:
; WINDOWS-LABEL: uf:
entry:
%div = udiv i32 %a, %b
%rem = urem i32 %a, %b
; EABI: __aeabi_uidivmod
; DARWIN: ___udivsi3
; DARWIN: mov [[sum:r[0-9]+]], r0
; DARWIN: mov [[div:r[0-9]+]], r0
; DARWIN: __umodsi3
; DARWIN: add [[sum]]{{.*}}r0
; DARWIN-DEFAULT: add [[sum:r[0-9]+]], r0, [[div]]
; DARWIN-O0: mov [[rem:r[0-9]+]], r0
; WINDOWS: __rt_udiv
; WINDOWS: mov [[div:r[0-9]+]], r0
; WINDOWS: __rt_udiv
; WINDOWS: mls [[rem:r[0-9]+]], r0,
; WINDOWS-DEFAULT: add [[div]], [[rem]]
%rem1 = urem i32 %b, %a
; EABI: __aeabi_uidivmod
; DARWIN: __umodsi3
; WINDOWS: __rt_udiv
; WINDOWS: mls [[rem1:r[0-9]+]], r0,
%add = add nuw i32 %rem, %div
%add2 = add nuw i32 %add, %rem1
; EABI: add r0{{.*}}r1
; DARWIN: add r0{{.*}}[[sum]]
; DARWIN-DEFAULT: add r0, [[sum]], r0
; DARWIN-O0: add [[sum:r[0-9]+]], [[rem]], [[div]]
; DARWIN-O0: add [[res:r[0-9]+]], [[sum]], r0
; WINDOWS-DEFAULT: add [[rem1]], [[div]]
; WINDOWS-O0: adds [[sum:r[0-9]+]], [[rem]], [[div]]
; WINDOWS-O0: add [[rem1]], [[sum]]
ret i32 %add2
}
define i64 @longf(i64 %a, i64 %b) {
; EABI-LABEL: longf:
; DARWIN-LABEL: longf:
; WINDOWS-LABEL: longf:
entry:
%div = sdiv i64 %a, %b
%rem = srem i64 %a, %b
@ -94,15 +153,22 @@ entry:
; DARWIN: mov [[div1:r[0-9]+]], r0
; DARWIN: mov [[div2:r[0-9]+]], r1
; DARWIN: __moddi3
; WINDOWS: __rt_sdiv64
; WINDOWS: mov [[div1:r[0-9]+]], r0
; WINDOWS: mov [[div2:r[0-9]+]], r1
; WINDOWS: __moddi3
%add = add nsw i64 %rem, %div
; DARWIN: adds r0{{.*}}[[div1]]
; DARWIN: adc r1{{.*}}[[div2]]
; WINDOWS: adds.w r0, r0, [[div1]]
; WINDOWS: adc.w r1, r1, [[div2]]
ret i64 %add
}
define i16 @shortf(i16 %a, i16 %b) {
; EABI-LABEL: shortf:
; DARWIN-LABEL: shortf:
; WINDOWS-LABEL: shortf:
entry:
%div = sdiv i16 %a, %b
%rem = srem i16 %a, %b
@ -110,14 +176,21 @@ entry:
; DARWIN: ___divsi3
; DARWIN: mov [[div1:r[0-9]+]], r0
; DARWIN: __modsi3
; WINDOWS: __rt_sdiv
; WINDOWS: mov [[div:r[0-9]+]], r0
; WINDOWS: __rt_sdiv
; WINDOWS: mls [[rem:r[0-9]+]], r0,
%add = add nsw i16 %rem, %div
; EABI: add r0, r1
; DARWIN: add r0{{.*}}[[div1]]
; WINDOWS: add [[rem]], [[div]]
ret i16 %add
}
define i32 @g1(i32 %a, i32 %b) {
; EABI-LABEL: g1:
; DARWIN-LABEL: g1:
; WINDOWS-LABEL: g1:
entry:
%div = sdiv i32 %a, %b
%rem = srem i32 %a, %b
@ -125,9 +198,14 @@ entry:
; DARWIN: ___divsi3
; DARWIN: mov [[sum:r[0-9]+]], r0
; DARWIN: __modsi3
; WINDOWS: __rt_sdiv
; WINDOWS: mov [[div:r[0-9]+]], r0
; WINDOWS: __rt_sdiv
; WINDOWS: mls [[rem:r[0-9]+]], r0,
%add = add nsw i32 %rem, %div
; EABI: add r0{{.*}}r1
; DARWIN: add r0{{.*}}[[sum]]
; WINDOWS: add [[rem]], [[div]]
ret i32 %add
}
@ -135,46 +213,61 @@ entry:
define i32 @g2(i32 %a, i32 %b) {
; EABI-LABEL: g2:
; DARWIN-LABEL: g2:
; WINDOWS-LABEL: g2:
entry:
%rem = srem i32 %a, %b
; EABI: __aeabi_idivmod
; DARWIN: __modsi3
; WINDOWS: __rt_sdiv
ret i32 %rem
; EABI: mov r0, r1
; WINDOWS: mls r0, r0,
}
define i32 @g3(i32 %a, i32 %b) {
; EABI-LABEL: g3:
; DARWIN-LABEL: g3:
; WINDOWS-LABEL: g3:
entry:
%rem = srem i32 %a, %b
; EABI: __aeabi_idivmod
; EABI: mov [[mod:r[0-9]+]], r1
; DARWIN: __modsi3
; DARWIN: mov [[sum:r[0-9]+]], r0
; WINDOWS: __rt_sdiv
; WINDOWS: mls [[rem:r[0-9]+]], r0,
%rem1 = srem i32 %b, %rem
; EABI: __aeabi_idivmod
; DARWIN: __modsi3
; WINDOWS: __rt_sdiv
; WINDOWS: mls [[rem1:r[0-9]+]], r0,
%add = add nsw i32 %rem1, %rem
; EABI: add r0, r1, [[mod]]
; DARWIN: add r0{{.*}}[[sum]]
; WINDOWS: add [[rem1]], [[rem]]
ret i32 %add
}
define i32 @g4(i32 %a, i32 %b) {
; EABI-LABEL: g4:
; DARWIN-LABEL: g4:
; WINDOWS-LABEL: g4:
entry:
%div = sdiv i32 %a, %b
; EABI: __aeabi_idiv{{$}}
; EABI: mov [[div:r[0-9]+]], r0
; DARWIN: ___divsi3
; DARWIN: mov [[sum:r[0-9]+]], r0
; WINDOWS: __rt_sdiv
; WINDOWS: mov [[div:r[0-9]+]], r0
%rem = srem i32 %b, %div
; EABI: __aeabi_idivmod
; DARWIN: __modsi3
; WINDOWS: __rt_sdiv
; WINDOWS: mls [[rem:r[0-9]+]], r0,
%add = add nsw i32 %rem, %div
; EABI: add r0, r1, [[div]]
; DARWIN: add r0{{.*}}[[sum]]
; WINDOWS: add [[rem]], [[div]]
ret i32 %add
}