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llvm-mingw/patches/llvm-0009.patch
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Martin Storsjö be1357f467 Backport more llvm patches from current master 
This fixes up handling of divisions on ARM/Windows, and consistently
does calls to helper functions using the windows/msvc names, instead
of the libgcc naming.
2016-11-01 11:13:50 +02:00

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From 20692f7f7548e98523818db6d83ca66e3ae0dedc Mon Sep 17 00:00:00 2001
From: Saleem Abdulrasool <compnerd@compnerd.org>
Date: Mon, 31 Oct 2016 22:12:37 +0000
Subject: [PATCH 9/9] CodeGen: further loosen -O0 CG for WoA division
Generate the slowest possible codepath for noopt CodeGen. Even trying to be
clever with the negated jump can cause out-of-range jumps. Use a wide branch
instead. Although the code is modelled simplistically, the later optimizations
would recombine the branching into `cbz` if possible. This re-enables the
previous optimization as well as hopefully gives us working code in all cases.
Addresses PR30356!
Cherry-picked from SVN trunk commit 285649, git mirror commit
f185e91e2bc8.
---
lib/Target/ARM/ARMISelLowering.cpp | 18 ++++++++++++-----
test/CodeGen/ARM/Windows/dbzchk.ll | 31 ++++++++++++++++--------------
test/CodeGen/ARM/Windows/division-range.ll | 4 ++--
test/CodeGen/ARM/Windows/division.ll | 20 +++++++++----------
4 files changed, 42 insertions(+), 31 deletions(-)
diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index f7b09fa..6d4e6d7 100644
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -8214,12 +8214,20 @@ ARMTargetLowering::EmitLowered__dbzchk(MachineInstr &MI,
ContBB->splice(ContBB->begin(), MBB,
std::next(MachineBasicBlock::iterator(MI)), MBB->end());
ContBB->transferSuccessorsAndUpdatePHIs(MBB);
-
- BuildMI(*MBB, MI, DL, TII->get(ARM::tCBNZ))
- .addReg(MI.getOperand(0).getReg())
- .addMBB(ContBB);
MBB->addSuccessor(ContBB);
- BuildMI(*MBB, MI, DL, TII->get(ARM::t__brkdiv0));
+
+ MachineBasicBlock *TrapBB = MF->CreateMachineBasicBlock();
+ BuildMI(TrapBB, DL, TII->get(ARM::t__brkdiv0));
+ MF->push_back(TrapBB);
+ MBB->addSuccessor(TrapBB);
+
+ AddDefaultPred(BuildMI(*MBB, MI, DL, TII->get(ARM::tCMPi8))
+ .addReg(MI.getOperand(0).getReg())
+ .addImm(0));
+ BuildMI(*MBB, MI, DL, TII->get(ARM::t2Bcc))
+ .addMBB(TrapBB)
+ .addImm(ARMCC::EQ)
+ .addReg(ARM::CPSR);
MI.eraseFromParent();
return ContBB;
diff --git a/test/CodeGen/ARM/Windows/dbzchk.ll b/test/CodeGen/ARM/Windows/dbzchk.ll
index af23cb2..aea3799 100644
--- a/test/CodeGen/ARM/Windows/dbzchk.ll
+++ b/test/CodeGen/ARM/Windows/dbzchk.ll
@@ -75,7 +75,7 @@ return:
; CHECK-MOD-DAG: BB#2
; RUN: llc -mtriple thumbv7--windows-itanium -print-machineinstrs=expand-isel-pseudos -verify-machineinstrs -filetype asm -o /dev/null %s 2>&1 | FileCheck %s -check-prefix CHECK-CFG
-; RUN: llc -mtriple thumbv7--windows-itanium -print-machineinstrs=expand-isel-pseudos -verify-machineinstrs -filetype asm -o - %s | FileCheck %s -check-prefix CHECK-CFG-ASM
+; RUN: llc -mtriple thumbv7--windows-itanium -verify-machineinstrs -filetype asm -o - %s | FileCheck %s -check-prefix CHECK-CFG-ASM
; unsigned c;
; extern unsigned long g(void);
@@ -119,21 +119,24 @@ attributes #0 = { optsize }
; CHECK-CFG-DAG: t2B <BB#3>
; CHECK-CFG-DAG: BB#2
-; CHECK-CFG-DAG: tCBNZ %vreg{{[0-9]}}, <BB#4>
-; CHECK-CFG-DAG: t__brkdiv0
+; CHECK-CFG-DAG: tCMPi8 %vreg{{[0-9]}}, 0
+; CHECK-CFG-DAG: t2Bcc <BB#5>
; CHECK-CFG-DAG: BB#4
; CHECK-CFG-DAG: BB#3
; CHECK-CFG-DAG: tBX_RET
+; CHECK-CFG-DAG: BB#5
+; CHECK-CFG-DAG: t__brkdiv0
+
; CHECK-CFG-ASM-LABEL: h:
-; CHECK-CFG-ASM: cbnz r{{[0-9]}}, .LBB2_2
-; CHECK-CFG-ASM: __brkdiv0
-; CHECK-CFG-ASM-LABEL: .LBB2_2:
+; CHECK-CFG-ASM: cbz r{{[0-9]}}, .LBB2_4
; CHECK-CFG-ASM: bl __rt_udiv
+; CHECK-CFG-ASM-LABEL: .LBB2_4:
+; CHECK-CFG-ASM: __brkdiv0
-; RUN: llc -O0 -mtriple thumbv7--windows-itanium -verify-machineinstrs -filetype asm -o - %s | FileCheck %s -check-prefix CHECK-WIN__DBZCHK
+; RUN: llc -O1 -mtriple thumbv7--windows-itanium -verify-machineinstrs -filetype asm -o - %s | FileCheck %s -check-prefix CHECK-WIN__DBZCHK
; long k(void);
; int l(void);
@@ -172,11 +175,11 @@ return:
}
; CHECK-WIN__DBZCHK-LABEL: j:
-; CHECK-WIN__DBZCHK: cbnz r{{[0-7]}}, .LBB
-; CHECK-WIN__DBZCHK-NOT: cbnz r8, .LBB
-; CHECK-WIN__DBZCHK-NOT: cbnz r9, .LBB
-; CHECK-WIN__DBZCHK-NOT: cbnz r10, .LBB
-; CHECK-WIN__DBZCHK-NOT: cbnz r11, .LBB
-; CHECK-WIN__DBZCHK-NOT: cbnz ip, .LBB
-; CHECK-WIN__DBZCHK-NOT: cbnz lr, .LBB
+; CHECK-WIN__DBZCHK: cbz r{{[0-7]}}, .LBB
+; CHECK-WIN__DBZCHK-NOT: cbz r8, .LBB
+; CHECK-WIN__DBZCHK-NOT: cbz r9, .LBB
+; CHECK-WIN__DBZCHK-NOT: cbz r10, .LBB
+; CHECK-WIN__DBZCHK-NOT: cbz r11, .LBB
+; CHECK-WIN__DBZCHK-NOT: cbz ip, .LBB
+; CHECK-WIN__DBZCHK-NOT: cbz lr, .LBB
diff --git a/test/CodeGen/ARM/Windows/division-range.ll b/test/CodeGen/ARM/Windows/division-range.ll
index 9b1920c..b14339e 100644
--- a/test/CodeGen/ARM/Windows/division-range.ll
+++ b/test/CodeGen/ARM/Windows/division-range.ll
@@ -9,7 +9,7 @@ entry:
ret i32 %div
}
-; CHECK: cbnz r1, #0
-; CHECK: __brkdiv0
+; CHECK: cmp r1, #0
+; CHECK: beq #
; CHECK: bl
diff --git a/test/CodeGen/ARM/Windows/division.ll b/test/CodeGen/ARM/Windows/division.ll
index b149cb0..10f86b0 100644
--- a/test/CodeGen/ARM/Windows/division.ll
+++ b/test/CodeGen/ARM/Windows/division.ll
@@ -8,9 +8,9 @@ entry:
}
; CHECK-LABEL: sdiv32:
-; CHECK: cbnz r0
-; CHECK: __brkdiv0
+; CHECK: cbz r0
; CHECK: bl __rt_sdiv
+; CHECK: __brkdiv0
define arm_aapcs_vfpcc i32 @udiv32(i32 %divisor, i32 %divident) {
entry:
@@ -19,9 +19,9 @@ entry:
}
; CHECK-LABEL: udiv32:
-; CHECK: cbnz r0
-; CHECK: __brkdiv0
+; CHECK: cbz r0
; CHECK: bl __rt_udiv
+; CHECK: __brkdiv0
define arm_aapcs_vfpcc i64 @sdiv64(i64 %divisor, i64 %divident) {
entry:
@@ -30,10 +30,10 @@ entry:
}
; CHECK-LABEL: sdiv64:
-; CHECK: orr.w r4, r0, r1
-; CHECK-NEXT: cbnz r4
-; CHECK: __brkdiv0
+; CHECK: orrs.w r4, r0, r1
+; CHECK-NEXT: beq
; CHECK: bl __rt_sdiv64
+; CHECK: __brkdiv0
define arm_aapcs_vfpcc i64 @udiv64(i64 %divisor, i64 %divident) {
entry:
@@ -42,8 +42,8 @@ entry:
}
; CHECK-LABEL: udiv64:
-; CHECK: orr.w r4, r0, r1
-; CHECK-NEXT: cbnz r4
-; CHECK: __brkdiv0
+; CHECK: orrs.w r4, r0, r1
+; CHECK-NEXT: beq
; CHECK: bl __rt_udiv64
+; CHECK: __brkdiv0
--
2.7.4
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