[llvm-branch-commits] [llvm] 923ca0b - [ARM][MachineOutliner] Fix costs model.

Yvan Roux via llvm-branch-commits llvm-branch-commits at lists.llvm.org
Thu Dec 17 07:16:13 PST 2020


Author: Yvan Roux
Date: 2020-12-17T16:08:23+01:00
New Revision: 923ca0b411f78a3d218ff660a5b7a8b9099bdaa4

URL: https://github.com/llvm/llvm-project/commit/923ca0b411f78a3d218ff660a5b7a8b9099bdaa4
DIFF: https://github.com/llvm/llvm-project/commit/923ca0b411f78a3d218ff660a5b7a8b9099bdaa4.diff

LOG: [ARM][MachineOutliner] Fix costs model.

Fix candidates calls costs models allocation and prepare stack fixups
handling.

Differential Revision: https://reviews.llvm.org/D92933

Added: 
    llvm/test/CodeGen/ARM/machine-outliner-stack-use.mir

Modified: 
    llvm/lib/Target/ARM/ARMBaseInstrInfo.cpp
    llvm/test/CodeGen/ARM/machine-outliner-calls.mir

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Target/ARM/ARMBaseInstrInfo.cpp b/llvm/lib/Target/ARM/ARMBaseInstrInfo.cpp
index 20823ee6d44a..2d937930d89f 100644
--- a/llvm/lib/Target/ARM/ARMBaseInstrInfo.cpp
+++ b/llvm/lib/Target/ARM/ARMBaseInstrInfo.cpp
@@ -5824,31 +5824,43 @@ outliner::OutlinedFunction ARMBaseInstrInfo::getOutliningCandidateInfo(
       else if (C.UsedInSequence.available(ARM::SP)) {
         NumBytesNoStackCalls += Costs.CallDefault;
         C.setCallInfo(MachineOutlinerDefault, Costs.CallDefault);
-        SetCandidateCallInfo(MachineOutlinerDefault, Costs.CallDefault);
         CandidatesWithoutStackFixups.push_back(C);
-      } else
-        return outliner::OutlinedFunction();
-    }
+      }
 
-    // Does every candidate's MBB contain a call?  If so, then we might have a
-    // call in the range.
-    if (FlagsSetInAll & MachineOutlinerMBBFlags::HasCalls) {
-      // check if the range contains a call.  These require a save + restore of
-      // the link register.
-      if (std::any_of(FirstCand.front(), FirstCand.back(),
-                      [](const MachineInstr &MI) { return MI.isCall(); }))
-        NumBytesToCreateFrame += Costs.SaveRestoreLROnStack;
-
-      // Handle the last instruction separately.  If it is tail call, then the
-      // last instruction is a call, we don't want to save + restore in this
-      // case.  However, it could be possible that the last instruction is a
-      // call without it being valid to tail call this sequence.  We should
-      // consider this as well.
-      else if (FrameID != MachineOutlinerThunk &&
-               FrameID != MachineOutlinerTailCall && FirstCand.back()->isCall())
-        NumBytesToCreateFrame += Costs.SaveRestoreLROnStack;
+      // If we outline this, we need to modify the stack. Pretend we don't
+      // outline this by saving all of its bytes.
+      else
+        NumBytesNoStackCalls += SequenceSize;
     }
-    RepeatedSequenceLocs = CandidatesWithoutStackFixups;
+
+    // If there are no places where we have to save LR, then note that we don't
+    // have to update the stack. Otherwise, give every candidate the default
+    // call type
+    if (NumBytesNoStackCalls <=
+        RepeatedSequenceLocs.size() * Costs.CallDefault) {
+      RepeatedSequenceLocs = CandidatesWithoutStackFixups;
+      FrameID = MachineOutlinerNoLRSave;
+    } else
+      SetCandidateCallInfo(MachineOutlinerDefault, Costs.CallDefault);
+  }
+
+  // Does every candidate's MBB contain a call?  If so, then we might have a
+  // call in the range.
+  if (FlagsSetInAll & MachineOutlinerMBBFlags::HasCalls) {
+    // check if the range contains a call.  These require a save + restore of
+    // the link register.
+    if (std::any_of(FirstCand.front(), FirstCand.back(),
+                    [](const MachineInstr &MI) { return MI.isCall(); }))
+      NumBytesToCreateFrame += Costs.SaveRestoreLROnStack;
+
+    // Handle the last instruction separately.  If it is tail call, then the
+    // last instruction is a call, we don't want to save + restore in this
+    // case.  However, it could be possible that the last instruction is a
+    // call without it being valid to tail call this sequence.  We should
+    // consider this as well.
+    else if (FrameID != MachineOutlinerThunk &&
+             FrameID != MachineOutlinerTailCall && FirstCand.back()->isCall())
+      NumBytesToCreateFrame += Costs.SaveRestoreLROnStack;
   }
 
   return outliner::OutlinedFunction(RepeatedSequenceLocs, SequenceSize,

diff  --git a/llvm/test/CodeGen/ARM/machine-outliner-calls.mir b/llvm/test/CodeGen/ARM/machine-outliner-calls.mir
index a9a2a1357e10..f18eeb81a35b 100644
--- a/llvm/test/CodeGen/ARM/machine-outliner-calls.mir
+++ b/llvm/test/CodeGen/ARM/machine-outliner-calls.mir
@@ -88,15 +88,15 @@ body:             |
   ; CHECK:   frame-setup CFI_INSTRUCTION def_cfa_offset 8
   ; CHECK:   frame-setup CFI_INSTRUCTION offset $lr, -4
   ; CHECK:   frame-setup CFI_INSTRUCTION offset $r7, -8
-  ; CHECK:   tBL 14 /* CC::al */, $noreg, @OUTLINED_FUNCTION_3
+  ; CHECK:   tBL 14 /* CC::al */, $noreg, @OUTLINED_FUNCTION_4
   ; CHECK: bb.1:
-  ; CHECK:   tBL 14 /* CC::al */, $noreg, @OUTLINED_FUNCTION_3
+  ; CHECK:   tBL 14 /* CC::al */, $noreg, @OUTLINED_FUNCTION_4
   ; CHECK: bb.2:
-  ; CHECK:   tBL 14 /* CC::al */, $noreg, @OUTLINED_FUNCTION_3
+  ; CHECK:   tBL 14 /* CC::al */, $noreg, @OUTLINED_FUNCTION_4
   ; CHECK: bb.3:
-  ; CHECK:   tBL 14 /* CC::al */, $noreg, @OUTLINED_FUNCTION_3
+  ; CHECK:   tBL 14 /* CC::al */, $noreg, @OUTLINED_FUNCTION_4
   ; CHECK: bb.4:
-  ; CHECK:   tBL 14 /* CC::al */, $noreg, @OUTLINED_FUNCTION_3
+  ; CHECK:   tBL 14 /* CC::al */, $noreg, @OUTLINED_FUNCTION_4
   ; CHECK: bb.5:
   ; CHECK:   $sp = frame-destroy t2LDMIA_RET $sp, 14 /* CC::al */, $noreg, def $r7, def $pc
   bb.0:
@@ -139,12 +139,14 @@ body:             |
   ; CHECK:   frame-setup CFI_INSTRUCTION def_cfa_offset 8
   ; CHECK:   frame-setup CFI_INSTRUCTION offset $lr, -4
   ; CHECK:   frame-setup CFI_INSTRUCTION offset $r4, -8
-  ; CHECK:   BL @OUTLINED_FUNCTION_2
+  ; CHECK:   BL @OUTLINED_FUNCTION_1
   ; CHECK: bb.1:
-  ; CHECK:   BL @OUTLINED_FUNCTION_2
+  ; CHECK:   BL @OUTLINED_FUNCTION_1
   ; CHECK: bb.2:
-  ; CHECK:   BL @OUTLINED_FUNCTION_2
+  ; CHECK:   BL @OUTLINED_FUNCTION_1
   ; CHECK: bb.3:
+  ; CHECK:   BL @OUTLINED_FUNCTION_1
+  ; CHECK: bb.4:
   ; CHECK:   $sp = frame-destroy LDMIA_UPD $sp, 14 /* CC::al */, $noreg, def $r4, def $lr
   ; CHECK:   BX_RET 14 /* CC::al */, $noreg
   bb.0:
@@ -172,6 +174,14 @@ body:             |
     $r4 = MOVi 2, 14, $noreg, $noreg
     BL @bar, implicit-def dead $lr, implicit $sp
   bb.3:
+    BL @bar, implicit-def dead $lr, implicit $sp
+    $r0 = MOVi 2, 14, $noreg, $noreg
+    $r1 = MOVi 2, 14, $noreg, $noreg
+    $r2 = MOVi 2, 14, $noreg, $noreg
+    $r3 = MOVi 2, 14, $noreg, $noreg
+    $r4 = MOVi 2, 14, $noreg, $noreg
+    BL @bar, implicit-def dead $lr, implicit $sp
+  bb.4:
     BX_RET 14, $noreg
 ...
 ---
@@ -186,12 +196,14 @@ body:             |
   ; CHECK:   frame-setup CFI_INSTRUCTION def_cfa_offset 8
   ; CHECK:   frame-setup CFI_INSTRUCTION offset $lr, -4
   ; CHECK:   frame-setup CFI_INSTRUCTION offset $r7, -8
-  ; CHECK:   tBL 14 /* CC::al */, $noreg, @OUTLINED_FUNCTION_4
+  ; CHECK:   tBL 14 /* CC::al */, $noreg, @OUTLINED_FUNCTION_3
   ; CHECK: bb.1:
-  ; CHECK:   tBL 14 /* CC::al */, $noreg, @OUTLINED_FUNCTION_4
+  ; CHECK:   tBL 14 /* CC::al */, $noreg, @OUTLINED_FUNCTION_3
   ; CHECK: bb.2:
-  ; CHECK:   tBL 14 /* CC::al */, $noreg, @OUTLINED_FUNCTION_4
+  ; CHECK:   tBL 14 /* CC::al */, $noreg, @OUTLINED_FUNCTION_3
   ; CHECK: bb.3:
+  ; CHECK:   tBL 14 /* CC::al */, $noreg, @OUTLINED_FUNCTION_3
+  ; CHECK: bb.4:
   ; CHECK:   $sp = frame-destroy t2LDMIA_RET $sp, 14 /* CC::al */, $noreg, def $r7, def $pc
   bb.0:
     tBL 14, $noreg, @bar, implicit-def dead $lr, implicit $sp
@@ -212,6 +224,12 @@ body:             |
     $r2 = t2MOVi 2, 14, $noreg, $noreg
     tBL 14, $noreg, @bar, implicit-def dead $lr, implicit $sp
   bb.3:
+    tBL 14, $noreg, @bar, implicit-def dead $lr, implicit $sp
+    $r0 = t2MOVi 2, 14, $noreg, $noreg
+    $r1 = t2MOVi 2, 14, $noreg, $noreg
+    $r2 = t2MOVi 2, 14, $noreg, $noreg
+    tBL 14, $noreg, @bar, implicit-def dead $lr, implicit $sp
+  bb.4:
     tBX_RET 14, $noreg
 ...
 ---
@@ -227,19 +245,19 @@ body:             |
   ; CHECK:   frame-setup CFI_INSTRUCTION offset $lr, -4
   ; CHECK:   frame-setup CFI_INSTRUCTION offset $r4, -8
   ; CHECK:   BL @"\01mcount", csr_aapcs, implicit-def dead $lr, implicit $sp
-  ; CHECK:   BL @OUTLINED_FUNCTION_1
+  ; CHECK:   BL @OUTLINED_FUNCTION_2
   ; CHECK: bb.1:
   ; CHECK:   BL @"\01mcount", csr_aapcs, implicit-def dead $lr, implicit $sp
-  ; CHECK:   BL @OUTLINED_FUNCTION_1
+  ; CHECK:   BL @OUTLINED_FUNCTION_2
   ; CHECK: bb.2:
   ; CHECK:   BL @"\01mcount", csr_aapcs, implicit-def dead $lr, implicit $sp
-  ; CHECK:   BL @OUTLINED_FUNCTION_1
+  ; CHECK:   BL @OUTLINED_FUNCTION_2
   ; CHECK: bb.3:
   ; CHECK:   BL @"\01mcount", csr_aapcs, implicit-def dead $lr, implicit $sp
-  ; CHECK:   BL @OUTLINED_FUNCTION_1
+  ; CHECK:   BL @OUTLINED_FUNCTION_2
   ; CHECK: bb.4:
   ; CHECK:   BL @"\01mcount", csr_aapcs, implicit-def dead $lr, implicit $sp
-  ; CHECK:   BL @OUTLINED_FUNCTION_1
+  ; CHECK:   BL @OUTLINED_FUNCTION_2
   ; CHECK: bb.5:
   ; CHECK:   $sp = frame-destroy LDMIA_UPD $sp, 14 /* CC::al */, $noreg, def $r4, def $lr
   ; CHECK:   BX_RET 14 /* CC::al */, $noreg
@@ -307,16 +325,6 @@ body:             |
 
   ; CHECK-LABEL: name: OUTLINED_FUNCTION_1
   ; CHECK: bb.0:
-  ; CHECK:   liveins: $r11, $r10, $r9, $r8, $r7, $r6, $r5, $d15, $d14, $d13, $d12, $d11, $d10, $d9, $d8
-  ; CHECK:   $r0 = MOVi 3, 14 /* CC::al */, $noreg, $noreg
-  ; CHECK:   $r1 = MOVi 3, 14 /* CC::al */, $noreg, $noreg
-  ; CHECK:   $r2 = MOVi 3, 14 /* CC::al */, $noreg, $noreg
-  ; CHECK:   $r3 = MOVi 3, 14 /* CC::al */, $noreg, $noreg
-  ; CHECK:   $r4 = MOVi 3, 14 /* CC::al */, $noreg, $noreg
-  ; CHECK:   MOVPCLR 14 /* CC::al */, $noreg
-
-  ; CHECK-LABEL: name: OUTLINED_FUNCTION_2
-  ; CHECK: bb.0:
   ; CHECK:   liveins: $r11, $r10, $r9, $r8, $r7, $r6, $r5, $d15, $d14, $d13, $d12, $d11, $d10, $d9, $d8, $lr
   ; CHECK:   early-clobber $sp = STR_PRE_IMM killed $lr, $sp, -8, 14 /* CC::al */, $noreg
   ; CHECK:   frame-setup CFI_INSTRUCTION def_cfa_offset 8
@@ -330,6 +338,16 @@ body:             |
   ; CHECK:   $lr, $sp = LDR_POST_IMM $sp, $noreg, 8, 14 /* CC::al */, $noreg
   ; CHECK:   TAILJMPd @bar, implicit $sp
 
+  ; CHECK-LABEL: name: OUTLINED_FUNCTION_2
+  ; CHECK: bb.0:
+  ; CHECK:   liveins: $r11, $r10, $r9, $r8, $r7, $r6, $r5, $d15, $d14, $d13, $d12, $d11, $d10, $d9, $d8
+  ; CHECK:   $r0 = MOVi 3, 14 /* CC::al */, $noreg, $noreg
+  ; CHECK:   $r1 = MOVi 3, 14 /* CC::al */, $noreg, $noreg
+  ; CHECK:   $r2 = MOVi 3, 14 /* CC::al */, $noreg, $noreg
+  ; CHECK:   $r3 = MOVi 3, 14 /* CC::al */, $noreg, $noreg
+  ; CHECK:   $r4 = MOVi 3, 14 /* CC::al */, $noreg, $noreg
+  ; CHECK:   MOVPCLR 14 /* CC::al */, $noreg
+
   ; CHECK-LABEL: name: OUTLINED_FUNCTION_3
   ; CHECK: bb.0:
   ; CHECK:   liveins: $r11, $r10, $r9, $r8, $r6, $r5, $r4, $d15, $d14, $d13, $d12, $d11, $d10, $d9, $d8, $lr
@@ -337,11 +355,11 @@ body:             |
   ; CHECK:   frame-setup CFI_INSTRUCTION def_cfa_offset 8
   ; CHECK:   frame-setup CFI_INSTRUCTION offset $lr, -8
   ; CHECK:   tBL 14 /* CC::al */, $noreg, @bar, implicit-def dead $lr, implicit $sp
-  ; CHECK:   $r0 = t2MOVi 1, 14 /* CC::al */, $noreg, $noreg
-  ; CHECK:   $r1 = t2MOVi 1, 14 /* CC::al */, $noreg, $noreg
-  ; CHECK:   $r2 = t2MOVi 1, 14 /* CC::al */, $noreg, $noreg
+  ; CHECK:   $r0 = t2MOVi 2, 14 /* CC::al */, $noreg, $noreg
+  ; CHECK:   $r1 = t2MOVi 2, 14 /* CC::al */, $noreg, $noreg
+  ; CHECK:   $r2 = t2MOVi 2, 14 /* CC::al */, $noreg, $noreg
   ; CHECK:   $lr, $sp = t2LDR_POST $sp, 8, 14 /* CC::al */, $noreg
-  ; CHECK:   tBX_RET 14 /* CC::al */, $noreg
+  ; CHECK:   tTAILJMPdND @bar, 14 /* CC::al */, $noreg, implicit $sp
 
   ; CHECK-LABEL: name: OUTLINED_FUNCTION_4
   ; CHECK: bb.0:
@@ -350,11 +368,11 @@ body:             |
   ; CHECK:   frame-setup CFI_INSTRUCTION def_cfa_offset 8
   ; CHECK:   frame-setup CFI_INSTRUCTION offset $lr, -8
   ; CHECK:   tBL 14 /* CC::al */, $noreg, @bar, implicit-def dead $lr, implicit $sp
-  ; CHECK:   $r0 = t2MOVi 2, 14 /* CC::al */, $noreg, $noreg
-  ; CHECK:   $r1 = t2MOVi 2, 14 /* CC::al */, $noreg, $noreg
-  ; CHECK:   $r2 = t2MOVi 2, 14 /* CC::al */, $noreg, $noreg
+  ; CHECK:   $r0 = t2MOVi 1, 14 /* CC::al */, $noreg, $noreg
+  ; CHECK:   $r1 = t2MOVi 1, 14 /* CC::al */, $noreg, $noreg
+  ; CHECK:   $r2 = t2MOVi 1, 14 /* CC::al */, $noreg, $noreg
   ; CHECK:   $lr, $sp = t2LDR_POST $sp, 8, 14 /* CC::al */, $noreg
-  ; CHECK:   tTAILJMPdND @bar, 14 /* CC::al */, $noreg, implicit $sp
+  ; CHECK:   tBX_RET 14 /* CC::al */, $noreg
 
 
 

diff  --git a/llvm/test/CodeGen/ARM/machine-outliner-stack-use.mir b/llvm/test/CodeGen/ARM/machine-outliner-stack-use.mir
new file mode 100644
index 000000000000..215925b861ec
--- /dev/null
+++ b/llvm/test/CodeGen/ARM/machine-outliner-stack-use.mir
@@ -0,0 +1,58 @@
+# RUN: llc -mtriple=arm-- -run-pass=machine-outliner -verify-machineinstrs \
+# RUN: %s -o - | FileCheck %s
+
+--- |
+  define void @stack_use_no_lr_save_1() #0 { ret void }
+  define void @stack_use_no_lr_save_2() #0 { ret void }
+
+  attributes #0 = { minsize optsize }
+...
+---
+
+name:           stack_use_no_lr_save_1
+tracksRegLiveness: true
+body:             |
+  bb.0:
+    ; CHECK-LABEL: name:           stack_use_no_lr_save_1
+    ; CHECK: BL @OUTLINED_FUNCTION_0
+    $r0 = MOVi 1, 14, $noreg, $noreg
+    $r0 = MOVi 1, 14, $noreg, $noreg
+    $r0 = LDRi12 $sp, 0, 14, $noreg
+    $r0 = LDRi12 $sp, 0, 14, $noreg
+    $r0 = LDRi12 $sp, 0, 14, $noreg
+    $r0 = MOVi 1, 14, $noreg, $noreg
+    $r0 = LDRi12 $sp, 0, 14, $noreg
+    $r0 = MOVi 1, 14, $noreg, $noreg
+  bb.1:
+    liveins: $r0, $r1, $r2, $r3, $r4, $r5, $r6, $r7, $r8, $r9, $r10, $r11
+    BX_RET 14, $noreg
+...
+---
+
+name:           stack_use_no_lr_save_2
+tracksRegLiveness: true
+body:             |
+  bb.0:
+    ; CHECK-LABEL: name:           stack_use_no_lr_save_2
+    ; CHECK: BL @OUTLINED_FUNCTION_0
+    $r0 = MOVi 1, 14, $noreg, $noreg
+    $r0 = MOVi 1, 14, $noreg, $noreg
+    $r0 = LDRi12 $sp, 0, 14, $noreg
+    $r0 = LDRi12 $sp, 0, 14, $noreg
+    $r0 = LDRi12 $sp, 0, 14, $noreg
+    $r0 = MOVi 1, 14, $noreg, $noreg
+    $r0 = LDRi12 $sp, 0, 14, $noreg
+    $r0 = MOVi 1, 14, $noreg, $noreg
+  bb.1:
+    BX_RET 14, $noreg
+
+    ;CHECK: name:           OUTLINED_FUNCTION_0
+    ;CHECK: $r0 = MOVi 1, 14 /* CC::al */, $noreg, $noreg
+    ;CHECK-NEXT: $r0 = MOVi 1, 14 /* CC::al */, $noreg, $noreg
+    ;CHECK-NEXT: $r0 = LDRi12 $sp, 0, 14 /* CC::al */, $noreg
+    ;CHECK-NEXT: $r0 = LDRi12 $sp, 0, 14 /* CC::al */, $noreg
+    ;CHECK-NEXT: $r0 = LDRi12 $sp, 0, 14 /* CC::al */, $noreg
+    ;CHECK-NEXT: $r0 = MOVi 1, 14 /* CC::al */, $noreg, $noreg
+    ;CHECK-NEXT: $r0 = LDRi12 $sp, 0, 14 /* CC::al */, $noreg
+    ;CHECK-NEXT: $r0 = MOVi 1, 14 /* CC::al */, $noreg, $noreg
+    ;CHECK-NEXT: MOVPCLR 14 /* CC::al */, $noreg


        


More information about the llvm-branch-commits mailing list