[ARM] Move GNUEABI divmod to __aeabi_divmod*

The GNU toolchain emits __aeabi_divmod for soft-divide on ARM cores
which happens to be a lot faster than __divsi3/__modsi3 when the core
has hardware divide instructions. Do the same here.

Fixes PR26450.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259657 91177308-0d34-0410-b5e6-96231b3b80d8

Author: rengolin

lib/Target/ARM/ARMISelLowering.cpp

@@ -784,7 +784,8 @@ ARMTargetLowering::ARMTargetLowering(const TargetMachine &TM,
   setOperationAction(ISD::SREM,  MVT::i32, Expand);
   setOperationAction(ISD::UREM,  MVT::i32, Expand);
   // Register based DivRem for AEABI (RTABI 4.2)
-  if (Subtarget->isTargetAEABI() || Subtarget->isTargetAndroid()) {
+  if (Subtarget->isTargetAEABI() || Subtarget->isTargetAndroid() ||
+      Subtarget->isTargetGNUAEABI()) {
     setOperationAction(ISD::SREM, MVT::i64, Custom);
     setOperationAction(ISD::UREM, MVT::i64, Custom);
 
@@ -11642,7 +11643,8 @@ static TargetLowering::ArgListTy getDivRemArgList(
 }
 
 SDValue ARMTargetLowering::LowerDivRem(SDValue Op, SelectionDAG &DAG) const {
-  assert((Subtarget->isTargetAEABI() || Subtarget->isTargetAndroid()) &&
+  assert((Subtarget->isTargetAEABI() || Subtarget->isTargetAndroid() ||
+          Subtarget->isTargetGNUAEABI()) &&
          "Register-based DivRem lowering only");
   unsigned Opcode = Op->getOpcode();
   assert((Opcode == ISD::SDIVREM || Opcode == ISD::UDIVREM) &&

test/CodeGen/ARM/divmod-eabi.ll

@@ -1,15 +1,14 @@
 ; RUN: llc -mtriple armv7-none-eabi %s -o - | FileCheck %s --check-prefix=EABI
 ; RUN: llc -mtriple armv7-none-eabihf %s -o - | FileCheck %s --check-prefix=EABI
-; Both "none-eabi" and "androideabi" must lower SREM/UREM to __aeabi_{u,i}divmod
+; 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-gnueabi %s -o - | FileCheck %s --check-prefix=GNU
+; RUN: llc -mtriple armv7-linux-gnueabi %s -o - | FileCheck %s --check-prefix=EABI
 ; RUN: llc -mtriple armv7-apple-darwin %s -o - | FileCheck %s --check-prefix=DARWIN
 ; 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
 
 define signext i16 @f16(i16 signext %a, i16 signext %b) {
 ; EABI-LABEL: f16:
-; GNU-LABEL: f16:
 ; DARWIN-LABEL: f16:
 entry:
   %conv = sext i16 %a to i32
@@ -19,189 +18,145 @@ entry:
 ; EABI: __aeabi_idivmod
 ; EABI: mov [[div:r[0-9]+]], r0
 ; EABI: mov [[rem:r[0-9]+]], r1
-; GNU: __aeabi_idiv
-; GNU: mov [[sum:r[0-9]+]], r0
-; GNU: __modsi3
-; GNU: add [[sum]]{{.*}}r0
 ; DARWIN: ___divsi3
 ; DARWIN: mov [[sum:r[0-9]+]], r0
 ; DARWIN: __modsi3
 ; DARWIN: add [[sum]]{{.*}}r0
   %rem8 = srem i32 %conv1, %conv
 ; EABI: __aeabi_idivmod
-; GNU: __modsi3
 ; DARWIN: __modsi3
   %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
-; GNU: add r0{{.*}}[[sum]]
-; GNU: sxth r0, r0
 ; DARWIN: add r0{{.*}}[[sum]]
 ; DARWIN: sxth r0, r0
   ret i16 %conv14
 }
 
 define i32 @f32(i32 %a, i32 %b) {
 ; EABI-LABEL: f32:
-; GNU-LABEL: f32:
 ; DARWIN-LABEL: f32:
 entry:
   %div = sdiv i32 %a, %b
   %rem = srem i32 %a, %b
 ; EABI: __aeabi_idivmod
 ; EABI: mov [[div:r[0-9]+]], r0
 ; EABI: mov [[rem:r[0-9]+]], r1
-; GNU: __aeabi_idiv
-; GNU: mov [[sum:r[0-9]+]], r0
-; GNU: __modsi3
-; GNU: add [[sum]]{{.*}}r0
 ; DARWIN: ___divsi3
 ; DARWIN: mov [[sum:r[0-9]+]], r0
 ; DARWIN: __modsi3
 ; DARWIN: add [[sum]]{{.*}}r0
   %rem1 = srem i32 %b, %a
 ; EABI: __aeabi_idivmod
-; GNU: __modsi3
 ; DARWIN: __modsi3
   %add = add nsw i32 %rem, %div
   %add2 = add nsw i32 %add, %rem1
 ; EABI: add r0{{.*}}r1
-; GNU: add r0{{.*}}[[sum]]
 ; DARWIN: add r0{{.*}}[[sum]]
   ret i32 %add2
 }
 
 define i32 @uf(i32 %a, i32 %b) {
 ; EABI-LABEL: uf:
-; GNU-LABEL: uf:
 ; DARWIN-LABEL: uf:
 entry:
   %div = udiv i32 %a, %b
   %rem = urem i32 %a, %b
 ; EABI: __aeabi_uidivmod
-; GNU: __aeabi_uidiv
-; GNU: mov [[sum:r[0-9]+]], r0
-; GNU: __umodsi3
-; GNU: add [[sum]]{{.*}}r0
 ; DARWIN: ___udivsi3
 ; DARWIN: mov [[sum:r[0-9]+]], r0
 ; DARWIN: __umodsi3
 ; DARWIN: add [[sum]]{{.*}}r0
   %rem1 = urem i32 %b, %a
 ; EABI: __aeabi_uidivmod
-; GNU: __umodsi3
 ; DARWIN: __umodsi3
   %add = add nuw i32 %rem, %div
   %add2 = add nuw i32 %add, %rem1
 ; EABI: add r0{{.*}}r1
-; GNU: add r0{{.*}}[[sum]]
 ; DARWIN: add r0{{.*}}[[sum]]
   ret i32 %add2
 }
 
 ; FIXME: AEABI is not lowering long u/srem into u/ldivmod
 define i64 @longf(i64 %a, i64 %b) {
 ; EABI-LABEL: longf:
-; GNU-LABEL: longf:
 ; DARWIN-LABEL: longf:
 entry:
   %div = sdiv i64 %a, %b
   %rem = srem i64 %a, %b
 ; EABI: __aeabi_ldivmod
-; GNU: __aeabi_ldivmod
-; GNU: mov [[div1:r[0-9]+]], r0
-; GNU: mov [[div2:r[0-9]+]], r1
 ; DARWIN: ___divdi3
 ; DARWIN: mov [[div1:r[0-9]+]], r0
 ; DARWIN: mov [[div2:r[0-9]+]], r1
 ; DARWIN: __moddi3
   %add = add nsw i64 %rem, %div
-; GNU: adds r0{{.*}}[[div1]]
-; GNU: adc r1{{.*}}[[div2]]
 ; DARWIN: adds r0{{.*}}[[div1]]
 ; DARWIN: adc r1{{.*}}[[div2]]
   ret i64 %add
 }
 
 define i32 @g1(i32 %a, i32 %b) {
 ; EABI-LABEL: g1:
-; GNU-LABEL: g1:
 ; DARWIN-LABEL: g1:
 entry:
   %div = sdiv i32 %a, %b
   %rem = srem i32 %a, %b
 ; EABI: __aeabi_idivmod
-; GNU: __aeabi_idiv
-; GNU: mov [[sum:r[0-9]+]], r0
-; GNU: __modsi3
 ; DARWIN: ___divsi3
 ; DARWIN: mov [[sum:r[0-9]+]], r0
 ; DARWIN: __modsi3
   %add = add nsw i32 %rem, %div
 ; EABI:	add	r0{{.*}}r1
-; GNU: add r0{{.*}}[[sum]]
 ; DARWIN: add r0{{.*}}[[sum]]
   ret i32 %add
 }
 
 ; On both Darwin and Gnu, this is just a call to __modsi3
 define i32 @g2(i32 %a, i32 %b) {
 ; EABI-LABEL: g2:
-; GNU-LABEL: g2:
 ; DARWIN-LABEL: g2:
 entry:
   %rem = srem i32 %a, %b
 ; EABI: __aeabi_idivmod
-; GNU: __modsi3
 ; DARWIN: __modsi3
   ret i32 %rem
 ; EABI:	mov	r0, r1
 }
 
 define i32 @g3(i32 %a, i32 %b) {
 ; EABI-LABEL: g3:
-; GNU-LABEL: g3:
 ; DARWIN-LABEL: g3:
 entry:
   %rem = srem i32 %a, %b
 ; EABI: __aeabi_idivmod
 ; EABI: mov [[mod:r[0-9]+]], r1
-; GNU: __modsi3
-; GNU: mov [[sum:r[0-9]+]], r0
 ; DARWIN: __modsi3
 ; DARWIN: mov [[sum:r[0-9]+]], r0
   %rem1 = srem i32 %b, %rem
 ; EABI: __aeabi_idivmod
-; GNU: __modsi3
 ; DARWIN: __modsi3
   %add = add nsw i32 %rem1, %rem
 ; EABI: add r0, r1, [[mod]]
-; GNU: add r0{{.*}}[[sum]]
 ; DARWIN: add r0{{.*}}[[sum]]
   ret i32 %add
 }
 
 define i32 @g4(i32 %a, i32 %b) {
 ; EABI-LABEL: g4:
-; GNU-LABEL: g4:
 ; DARWIN-LABEL: g4:
 entry:
   %div = sdiv i32 %a, %b
 ; EABI: __aeabi_idiv{{$}}
 ; EABI: mov [[div:r[0-9]+]], r0
-; GNU: __aeabi_idiv
-; GNU: mov [[sum:r[0-9]+]], r0
 ; DARWIN: ___divsi3
 ; DARWIN: mov [[sum:r[0-9]+]], r0
   %rem = srem i32 %b, %div
 ; EABI: __aeabi_idivmod
-; GNU: __modsi3
 ; DARWIN: __modsi3
   %add = add nsw i32 %rem, %div
 ; EABI: add r0, r1, [[div]]
-; GNU: add r0{{.*}}[[sum]]
 ; DARWIN: add r0{{.*}}[[sum]]
   ret i32 %add
 }