[TailDuplicator] Fix copy instruction emitting into the wrong block.

The code for duplicating instructions could sometimes try to emit copies
intended to deal with unconstrainable register classes to the tail block of the
original instruction, rather than before the newly cloned instruction in the
predecessor block.

This was exposed by GlobalISel on arm64.

Differential Revision: https://reviews.llvm.org/D64049

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@364888 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/TailDuplicator.cpp b/lib/CodeGen/TailDuplicator.cpp
index 4d3e02e3174cb470844fa72bc701a11f44fd5163..a0590a8a6cc68fed9a200ecc08bfc30ac2424a8e 100644 (file)
--- a/lib/CodeGen/TailDuplicator.cpp
+++ b/lib/CodeGen/TailDuplicator.cpp
@@ -434,7 +434,7 @@ void TailDuplicator::duplicateInstruction(
             if (NewRC == nullptr)
               NewRC = OrigRC;
             unsigned NewReg = MRI->createVirtualRegister(NewRC);
-            BuildMI(*PredBB, MI, MI->getDebugLoc(),
+            BuildMI(*PredBB, NewMI, NewMI.getDebugLoc(),
                     TII->get(TargetOpcode::COPY), NewReg)
                 .addReg(VI->second.Reg, 0, VI->second.SubReg);
             LocalVRMap.erase(VI);

diff --git a/test/CodeGen/AArch64/taildup-inst-dup-loc.mir b/test/CodeGen/AArch64/taildup-inst-dup-loc.mir
new file mode 100644 (file)
index 0000000..5954801
--- /dev/null
+++ b/test/CodeGen/AArch64/taildup-inst-dup-loc.mir
@@ -0,0 +1,125 @@
+# RUN: llc -mtriple aarch64 -run-pass=early-tailduplication -verify-machineinstrs %s -o - 2>&1 | FileCheck %s
+---
+name:            pluto
+tracksRegLiveness: true
+body:             |
+  ; This test checks that the COPY3 and COPY4 copies are correctly placed in the bb.5 block,
+  ; instead of crashing.
+
+  ; CHECK-LABEL: name: pluto
+  ; CHECK: bb.0:
+  ; CHECK:   successors: %bb.1(0x40000000), %bb.2(0x40000000)
+  ; CHECK:   liveins: $x0
+  ; CHECK:   [[DEF:%[0-9]+]]:gpr32 = IMPLICIT_DEF
+  ; CHECK:   [[DEF1:%[0-9]+]]:gpr32common = IMPLICIT_DEF
+  ; CHECK:   [[DEF2:%[0-9]+]]:gpr64 = IMPLICIT_DEF
+  ; CHECK:   [[DEF3:%[0-9]+]]:gpr64common = IMPLICIT_DEF
+  ; CHECK:   [[MOVi32imm:%[0-9]+]]:gpr32 = MOVi32imm 1
+  ; CHECK:   [[FMOVD0_:%[0-9]+]]:fpr64 = FMOVD0
+  ; CHECK:   TBNZW [[DEF]], 0, %bb.1
+  ; CHECK:   B %bb.2
+  ; CHECK: bb.1:
+  ; CHECK:   successors: %bb.9(0x80000000)
+  ; CHECK:   [[LDRXui:%[0-9]+]]:gpr64 = LDRXui [[DEF3]], 0 :: (load 8 from `i64* undef`)
+  ; CHECK:   B %bb.9
+  ; CHECK: bb.2:
+  ; CHECK:   successors: %bb.3(0x40000000), %bb.4(0x40000000)
+  ; CHECK:   $wzr = SUBSWri [[DEF1]], 19, 0, implicit-def $nzcv
+  ; CHECK:   [[CSINCWr:%[0-9]+]]:gpr32 = CSINCWr $wzr, $wzr, 1, implicit $nzcv
+  ; CHECK:   TBNZW [[CSINCWr]], 0, %bb.3
+  ; CHECK:   B %bb.4
+  ; CHECK: bb.3:
+  ; CHECK:   successors: %bb.9(0x80000000)
+  ; CHECK:   [[SCVTFUXDri:%[0-9]+]]:fpr64 = SCVTFUXDri [[DEF2]]
+  ; CHECK:   [[COPY:%[0-9]+]]:gpr64 = COPY [[SCVTFUXDri]]
+  ; CHECK:   [[COPY1:%[0-9]+]]:fpr64 = COPY [[SCVTFUXDri]]
+  ; CHECK:   B %bb.9
+  ; CHECK: bb.4:
+  ; CHECK:   successors: %bb.5(0x40000000), %bb.8(0x40000000)
+  ; CHECK:   TBNZW [[DEF]], 0, %bb.5
+  ; CHECK:   B %bb.8
+  ; CHECK: bb.5:
+  ; CHECK:   successors: %bb.9(0x80000000)
+  ; CHECK:   [[COPY2:%[0-9]+]]:fpr64 = COPY [[DEF2]]
+  ; CHECK:   [[COPY3:%[0-9]+]]:gpr64 = COPY [[COPY2]]
+  ; CHECK:   [[COPY4:%[0-9]+]]:fpr64 = COPY [[DEF2]]
+  ; CHECK:   B %bb.9
+  ; CHECK: bb.8:
+  ; CHECK:   successors: %bb.9(0x80000000)
+  ; CHECK: bb.9:
+  ; CHECK:   [[PHI:%[0-9]+]]:gpr64 = PHI [[LDRXui]], %bb.1, [[FMOVD0_]], %bb.8, [[COPY]], %bb.3, [[COPY3]], %bb.5
+  ; CHECK:   ADJCALLSTACKDOWN 0, 0, implicit-def $sp, implicit $sp
+  ; CHECK:   $d0 = COPY [[PHI]]
+  ; CHECK:   BL @pluto, csr_aarch64_aapcs, implicit-def $lr, implicit $sp, implicit $d0, implicit-def $d0
+  ; CHECK:   ADJCALLSTACKUP 0, 0, implicit-def $sp, implicit $sp
+  ; CHECK:   $w0 = COPY [[MOVi32imm]]
+  ; CHECK:   RET_ReallyLR implicit $w0
+
+  bb.1:
+    successors: %bb.2(0x40000000), %bb.3(0x40000000)
+    liveins: $x0
+
+    %1:gpr32 = IMPLICIT_DEF
+    %2:gpr32common = IMPLICIT_DEF
+    %5:gpr64 = IMPLICIT_DEF
+    %9:gpr64common = IMPLICIT_DEF
+    %13:gpr32 = MOVi32imm 1
+    %14:fpr64 = FMOVD0
+    TBNZW %1, 0, %bb.2
+    B %bb.3
+
+  bb.2:
+    successors: %bb.8(0x80000000)
+
+    %8:gpr64 = LDRXui %9, 0 :: (load 8 from `i64* undef`)
+    B %bb.8
+
+  bb.3:
+    successors: %bb.4(0x40000000), %bb.5(0x40000000)
+
+    $wzr = SUBSWri %2, 19, 0, implicit-def $nzcv
+    %15:gpr32 = CSINCWr $wzr, $wzr, 1, implicit $nzcv
+    TBNZW %15, 0, %bb.4
+    B %bb.5
+
+  bb.4:
+    successors: %bb.7(0x80000000)
+
+    %6:fpr64 = SCVTFUXDri %5
+    B %bb.7
+
+  bb.5:
+    successors: %bb.6(0x40000000), %bb.9(0x40000000)
+
+    TBNZW %1, 0, %bb.6
+    B %bb.9
+
+  bb.6:
+    successors: %bb.7(0x80000000)
+
+
+  bb.7:
+    successors: %bb.8(0x80000000)
+
+    %7:fpr64 = PHI %6, %bb.4, %5, %bb.6
+
+  bb.8:
+    successors: %bb.10(0x80000000)
+
+    %10:gpr64 = PHI %8, %bb.2, %7, %bb.7
+    B %bb.10
+
+  bb.9:
+    successors: %bb.10(0x80000000)
+
+
+  bb.10:
+    %11:gpr64 = PHI %10, %bb.8, %14, %bb.9
+    ADJCALLSTACKDOWN 0, 0, implicit-def $sp, implicit $sp
+    $d0 = COPY %11
+    BL @pluto, csr_aarch64_aapcs, implicit-def $lr, implicit $sp, implicit $d0, implicit-def $d0
+    ADJCALLSTACKUP 0, 0, implicit-def $sp, implicit $sp
+    $w0 = COPY %13
+    RET_ReallyLR implicit $w0
+
+...