Merging r294129:

------------------------------------------------------------------------
r294129 | gberry | 2017-02-05 10:28:14 -0800 (Sun, 05 Feb 2017) | 16 lines

[SelectionDAG] In InstrEmitter, handle EXTRACT_SUBREG of a physical register.

Summary:
Without this change, the getVR() call would hit an assert since it was
being passed a physical register.

Update the AArch64/ldst-opt.ll test with a case that triggers this
behavior by adding a run with strict-align, which causes an unaligned
STR XZR instruction to be split into byte stores, creating an
EXTRACT_SUBREG of XZR that triggers the original problem.

Reviewers: bogner, qcolombet, MatzeB, atrick

Subscribers: aemerson, mcrosier, llvm-commits

Differential Revision: https://reviews.llvm.org/D29495
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_40@295250 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/SelectionDAG/InstrEmitter.cpp b/lib/CodeGen/SelectionDAG/InstrEmitter.cpp
index 3b91e58879b49e6d09ebc55c4be0ead8174d2560..4a9042cfb3f447bb08da181e2aa480d4146d5270 100644 (file)
--- a/lib/CodeGen/SelectionDAG/InstrEmitter.cpp
+++ b/lib/CodeGen/SelectionDAG/InstrEmitter.cpp
@@ -502,8 +502,17 @@ void InstrEmitter::EmitSubregNode(SDNode *Node,
     const TargetRegisterClass *TRC =
       TLI->getRegClassFor(Node->getSimpleValueType(0));
 
-    unsigned VReg = getVR(Node->getOperand(0), VRBaseMap);
-    MachineInstr *DefMI = MRI->getVRegDef(VReg);
+    unsigned Reg;
+    MachineInstr *DefMI;
+    RegisterSDNode *R = dyn_cast<RegisterSDNode>(Node->getOperand(0));
+    if (R && TargetRegisterInfo::isPhysicalRegister(R->getReg())) {
+      Reg = R->getReg();
+      DefMI = nullptr;
+    } else {
+      Reg = getVR(Node->getOperand(0), VRBaseMap);
+      DefMI = MRI->getVRegDef(Reg);
+    }
+
     unsigned SrcReg, DstReg, DefSubIdx;
     if (DefMI &&
         TII->isCoalescableExtInstr(*DefMI, SrcReg, DstReg, DefSubIdx) &&
@@ -519,20 +528,26 @@ void InstrEmitter::EmitSubregNode(SDNode *Node,
               TII->get(TargetOpcode::COPY), VRBase).addReg(SrcReg);
       MRI->clearKillFlags(SrcReg);
     } else {
-      // VReg may not support a SubIdx sub-register, and we may need to
+      // Reg may not support a SubIdx sub-register, and we may need to
       // constrain its register class or issue a COPY to a compatible register
       // class.
-      VReg = ConstrainForSubReg(VReg, SubIdx,
-                                Node->getOperand(0).getSimpleValueType(),
-                                Node->getDebugLoc());
+      if (TargetRegisterInfo::isVirtualRegister(Reg))
+        Reg = ConstrainForSubReg(Reg, SubIdx,
+                                 Node->getOperand(0).getSimpleValueType(),
+                                 Node->getDebugLoc());
 
       // Create the destreg if it is missing.
       if (VRBase == 0)
         VRBase = MRI->createVirtualRegister(TRC);
 
       // Create the extract_subreg machine instruction.
-      BuildMI(*MBB, InsertPos, Node->getDebugLoc(),
-              TII->get(TargetOpcode::COPY), VRBase).addReg(VReg, 0, SubIdx);
+      MachineInstrBuilder CopyMI =
+          BuildMI(*MBB, InsertPos, Node->getDebugLoc(),
+                  TII->get(TargetOpcode::COPY), VRBase);
+      if (TargetRegisterInfo::isVirtualRegister(Reg))
+        CopyMI.addReg(Reg, 0, SubIdx);
+      else
+        CopyMI.addReg(TRI->getSubReg(Reg, SubIdx));
     }
   } else if (Opc == TargetOpcode::INSERT_SUBREG ||
              Opc == TargetOpcode::SUBREG_TO_REG) {

diff --git a/test/CodeGen/AArch64/ldst-opt.ll b/test/CodeGen/AArch64/ldst-opt.ll
index 81e4b19e6eea2dec879473c450ca2e2a01069e38..b09fab8d8b465825c0160dc1725e8576c928886a 100644 (file)
--- a/test/CodeGen/AArch64/ldst-opt.ll
+++ b/test/CodeGen/AArch64/ldst-opt.ll
@@ -1,4 +1,5 @@
-; RUN: llc -mtriple=aarch64-linux-gnu -aarch64-enable-atomic-cfg-tidy=0 -disable-lsr -verify-machineinstrs -o - %s | FileCheck %s
+; RUN: llc -mtriple=aarch64-linux-gnu -aarch64-enable-atomic-cfg-tidy=0 -disable-lsr -verify-machineinstrs -o - %s | FileCheck --check-prefix=CHECK --check-prefix=NOSTRICTALIGN %s
+; RUN: llc -mtriple=aarch64-linux-gnu -mattr=+strict-align -aarch64-enable-atomic-cfg-tidy=0 -disable-lsr -verify-machineinstrs -o - %s | FileCheck --check-prefix=CHECK --check-prefix=STRICTALIGN %s
 
 ; This file contains tests for the AArch64 load/store optimizer.
 
@@ -119,7 +120,7 @@ define void @load-pre-indexed-doubleword(%struct.doubleword* %ptr) nounwind {
 ; CHECK: ldr x{{[0-9]+}}, [x{{[0-9]+}}, #32]!
 entry:
   %a = getelementptr inbounds %struct.doubleword, %struct.doubleword* %ptr, i64 0, i32 1, i32 0
-  %add = load i64, i64* %a, align 4
+  %add = load i64, i64* %a, align 8
   br label %bar
 bar:
   %c = getelementptr inbounds %struct.doubleword, %struct.doubleword* %ptr, i64 0, i32 1
@@ -132,7 +133,7 @@ define void @store-pre-indexed-doubleword(%struct.doubleword* %ptr, i64 %val) no
 ; CHECK: str x{{[0-9]+}}, [x{{[0-9]+}}, #32]!
 entry:
   %a = getelementptr inbounds %struct.doubleword, %struct.doubleword* %ptr, i64 0, i32 1, i32 0
-  store i64 %val, i64* %a, align 4
+  store i64 %val, i64* %a, align 8
   br label %bar
 bar:
   %c = getelementptr inbounds %struct.doubleword, %struct.doubleword* %ptr, i64 0, i32 1
@@ -147,7 +148,7 @@ define void @load-pre-indexed-quadword(%struct.quadword* %ptr) nounwind {
 ; CHECK: ldr q{{[0-9]+}}, [x{{[0-9]+}}, #32]!
 entry:
   %a = getelementptr inbounds %struct.quadword, %struct.quadword* %ptr, i64 0, i32 1, i32 0
-  %add = load fp128, fp128* %a, align 4
+  %add = load fp128, fp128* %a, align 16
   br label %bar
 bar:
   %c = getelementptr inbounds %struct.quadword, %struct.quadword* %ptr, i64 0, i32 1
@@ -160,7 +161,7 @@ define void @store-pre-indexed-quadword(%struct.quadword* %ptr, fp128 %val) noun
 ; CHECK: str q{{[0-9]+}}, [x{{[0-9]+}}, #32]!
 entry:
   %a = getelementptr inbounds %struct.quadword, %struct.quadword* %ptr, i64 0, i32 1, i32 0
-  store fp128 %val, fp128* %a, align 4
+  store fp128 %val, fp128* %a, align 16
   br label %bar
 bar:
   %c = getelementptr inbounds %struct.quadword, %struct.quadword* %ptr, i64 0, i32 1
@@ -203,7 +204,7 @@ define void @load-pre-indexed-double(%struct.double* %ptr) nounwind {
 ; CHECK: ldr d{{[0-9]+}}, [x{{[0-9]+}}, #32]!
 entry:
   %a = getelementptr inbounds %struct.double, %struct.double* %ptr, i64 0, i32 1, i32 0
-  %add = load double, double* %a, align 4
+  %add = load double, double* %a, align 8
   br label %bar
 bar:
   %c = getelementptr inbounds %struct.double, %struct.double* %ptr, i64 0, i32 1
@@ -216,7 +217,7 @@ define void @store-pre-indexed-double(%struct.double* %ptr, double %val) nounwin
 ; CHECK: str d{{[0-9]+}}, [x{{[0-9]+}}, #32]!
 entry:
   %a = getelementptr inbounds %struct.double, %struct.double* %ptr, i64 0, i32 1, i32 0
-  store double %val, double* %a, align 4
+  store double %val, double* %a, align 8
   br label %bar
 bar:
   %c = getelementptr inbounds %struct.double, %struct.double* %ptr, i64 0, i32 1
@@ -1340,7 +1341,8 @@ end:
 define void @merge_zr32(i32* %p) {
 ; CHECK-LABEL: merge_zr32:
 ; CHECK: // %entry
-; CHECK-NEXT: str xzr, [x{{[0-9]+}}]
+; NOSTRICTALIGN-NEXT: str xzr, [x{{[0-9]+}}]
+; STRICTALIGN-NEXT: stp wzr, wzr, [x{{[0-9]+}}]
 ; CHECK-NEXT: ret
 entry:
   store i32 0, i32* %p
@@ -1349,11 +1351,13 @@ entry:
   ret void
 }
 
-; Same sa merge_zr32 but the merged stores should also get paried.
+; Same as merge_zr32 but the merged stores should also get paried.
 define void @merge_zr32_2(i32* %p) {
 ; CHECK-LABEL: merge_zr32_2:
 ; CHECK: // %entry
-; CHECK-NEXT: stp xzr, xzr, [x{{[0-9]+}}]
+; NOSTRICTALIGN-NEXT: stp xzr, xzr, [x{{[0-9]+}}]
+; STRICTALIGN-NEXT: stp wzr, wzr, [x{{[0-9]+}}]
+; STRICTALIGN-NEXT: stp wzr, wzr, [x{{[0-9]+}}, #8]
 ; CHECK-NEXT: ret
 entry:
   store i32 0, i32* %p
@@ -1370,7 +1374,11 @@ entry:
 define void @merge_zr32_2_offset(i32* %p) {
 ; CHECK-LABEL: merge_zr32_2_offset:
 ; CHECK: // %entry
-; CHECK-NEXT: stp xzr, xzr, [x{{[0-9]+}}, #504]
+; NOSTRICTALIGN-NEXT: stp xzr, xzr, [x{{[0-9]+}}, #504]
+; STRICTALIGN-NEXT: str wzr, [x{{[0-9]+}}, #504]
+; STRICTALIGN-NEXT: str wzr, [x{{[0-9]+}}, #508]
+; STRICTALIGN-NEXT: str wzr, [x{{[0-9]+}}, #512]
+; STRICTALIGN-NEXT: str wzr, [x{{[0-9]+}}, #516]
 ; CHECK-NEXT: ret
 entry:
   %p0 = getelementptr i32, i32* %p, i32 126
@@ -1390,8 +1398,12 @@ entry:
 define void @no_merge_zr32_2_offset(i32* %p) {
 ; CHECK-LABEL: no_merge_zr32_2_offset:
 ; CHECK: // %entry
-; CHECK-NEXT: movi v[[REG:[0-9]]].2d, #0000000000000000
-; CHECK-NEXT: str q[[REG]], [x{{[0-9]+}}, #4096]
+; NOSTRICTALIGN-NEXT: movi v[[REG:[0-9]]].2d, #0000000000000000
+; NOSTRICTALIGN-NEXT: str q[[REG]], [x{{[0-9]+}}, #4096]
+; STRICTALIGN-NEXT: str wzr, [x{{[0-9]+}}, #4096]
+; STRICTALIGN-NEXT: str wzr, [x{{[0-9]+}}, #4100]
+; STRICTALIGN-NEXT: str wzr, [x{{[0-9]+}}, #4104]
+; STRICTALIGN-NEXT: str wzr, [x{{[0-9]+}}, #4108]
 ; CHECK-NEXT: ret
 entry:
   %p0 = getelementptr i32, i32* %p, i32 1024
@@ -1411,8 +1423,12 @@ entry:
 define void @merge_zr32_3(i32* %p) {
 ; CHECK-LABEL: merge_zr32_3:
 ; CHECK: // %entry
-; CHECK-NEXT: movi v[[REG:[0-9]]].2d, #0000000000000000
-; CHECK-NEXT: stp q[[REG]], q[[REG]], [x{{[0-9]+}}]
+; NOSTRICTALIGN-NEXT: movi v[[REG:[0-9]]].2d, #0000000000000000
+; NOSTRICTALIGN-NEXT: stp q[[REG]], q[[REG]], [x{{[0-9]+}}]
+; STRICTALIGN-NEXT: stp wzr, wzr, [x{{[0-9]+}}]
+; STRICTALIGN-NEXT: stp wzr, wzr, [x{{[0-9]+}}, #8]
+; STRICTALIGN-NEXT: stp wzr, wzr, [x{{[0-9]+}}, #16]
+; STRICTALIGN-NEXT: stp wzr, wzr, [x{{[0-9]+}}, #24]
 ; CHECK-NEXT: ret
 entry:
   store i32 0, i32* %p
@@ -1437,7 +1453,8 @@ entry:
 define void @merge_zr32_2vec(<2 x i32>* %p) {
 ; CHECK-LABEL: merge_zr32_2vec:
 ; CHECK: // %entry
-; CHECK-NEXT: str xzr, [x{{[0-9]+}}]
+; NOSTRICTALIGN-NEXT: str xzr, [x{{[0-9]+}}]
+; STRICTALIGN-NEXT: stp wzr, wzr, [x{{[0-9]+}}]
 ; CHECK-NEXT: ret
 entry:
   store <2 x i32> zeroinitializer, <2 x i32>* %p
@@ -1448,8 +1465,10 @@ entry:
 define void @merge_zr32_3vec(<3 x i32>* %p) {
 ; CHECK-LABEL: merge_zr32_3vec:
 ; CHECK: // %entry
-; CHECK-NEXT: str xzr, [x{{[0-9]+}}]
-; CHECK-NEXT: str wzr, [x{{[0-9]+}}, #8]
+; NOSTRICTALIGN-NEXT: str xzr, [x{{[0-9]+}}]
+; NOSTRICTALIGN-NEXT: str wzr, [x{{[0-9]+}}, #8]
+; STRICTALIGN-NEXT: stp wzr, wzr, [x{{[0-9]+}}]
+; STRICTALIGN-NEXT: str wzr, [x{{[0-9]+}}, #8]
 ; CHECK-NEXT: ret
 entry:
   store <3 x i32> zeroinitializer, <3 x i32>* %p
@@ -1460,7 +1479,9 @@ entry:
 define void @merge_zr32_4vec(<4 x i32>* %p) {
 ; CHECK-LABEL: merge_zr32_4vec:
 ; CHECK: // %entry
-; CHECK-NEXT: stp xzr, xzr, [x{{[0-9]+}}]
+; NOSTRICTALIGN-NEXT: stp xzr, xzr, [x{{[0-9]+}}]
+; STRICTALIGN-NEXT: stp wzr, wzr, [x{{[0-9]+}}]
+; STRICTALIGN-NEXT: stp wzr, wzr, [x{{[0-9]+}}, #8]
 ; CHECK-NEXT: ret
 entry:
   store <4 x i32> zeroinitializer, <4 x i32>* %p
@@ -1471,7 +1492,8 @@ entry:
 define void @merge_zr32_2vecf(<2 x float>* %p) {
 ; CHECK-LABEL: merge_zr32_2vecf:
 ; CHECK: // %entry
-; CHECK-NEXT: str xzr, [x{{[0-9]+}}]
+; NOSTRICTALIGN-NEXT: str xzr, [x{{[0-9]+}}]
+; STRICTALIGN-NEXT: stp wzr, wzr, [x{{[0-9]+}}]
 ; CHECK-NEXT: ret
 entry:
   store <2 x float> zeroinitializer, <2 x float>* %p
@@ -1482,7 +1504,9 @@ entry:
 define void @merge_zr32_4vecf(<4 x float>* %p) {
 ; CHECK-LABEL: merge_zr32_4vecf:
 ; CHECK: // %entry
-; CHECK-NEXT: stp xzr, xzr, [x{{[0-9]+}}]
+; NOSTRICTALIGN-NEXT: stp xzr, xzr, [x{{[0-9]+}}]
+; STRICTALIGN-NEXT: stp wzr, wzr, [x{{[0-9]+}}]
+; STRICTALIGN-NEXT: stp wzr, wzr, [x{{[0-9]+}}, #8]
 ; CHECK-NEXT: ret
 entry:
   store <4 x float> zeroinitializer, <4 x float>* %p
@@ -1502,13 +1526,42 @@ entry:
   ret void
 }
 
+; Similar to merge_zr32, but for 64-bit values and with unaligned stores.
+define void @merge_zr64_unalign(<2 x i64>* %p) {
+; CHECK-LABEL: merge_zr64_unalign:
+; CHECK: // %entry
+; NOSTRICTALIGN-NEXT: stp xzr, xzr, [x{{[0-9]+}}]
+; STRICTALIGN: strb wzr,
+; STRICTALIGN: strb
+; STRICTALIGN: strb
+; STRICTALIGN: strb
+; STRICTALIGN: strb
+; STRICTALIGN: strb
+; STRICTALIGN: strb
+; STRICTALIGN: strb
+; STRICTALIGN: strb
+; STRICTALIGN: strb
+; STRICTALIGN: strb
+; STRICTALIGN: strb
+; STRICTALIGN: strb
+; STRICTALIGN: strb
+; STRICTALIGN: strb
+; STRICTALIGN: strb
+; CHECK-NEXT: ret
+entry:
+  store <2 x i64> zeroinitializer, <2 x i64>* %p, align 1
+  ret void
+}
+
 ; Similar to merge_zr32_3, replaceZeroVectorStore should not split the
 ; vector store since the zero constant vector has multiple uses.
 define void @merge_zr64_2(i64* %p) {
 ; CHECK-LABEL: merge_zr64_2:
 ; CHECK: // %entry
-; CHECK-NEXT: movi v[[REG:[0-9]]].2d, #0000000000000000
-; CHECK-NEXT: stp q[[REG]], q[[REG]], [x{{[0-9]+}}]
+; NOSTRICTALIGN-NEXT: movi v[[REG:[0-9]]].2d, #0000000000000000
+; NOSTRICTALIGN-NEXT: stp q[[REG]], q[[REG]], [x{{[0-9]+}}]
+; STRICTALIGN-NEXT: stp xzr, xzr, [x{{[0-9]+}}]
+; STRICTALIGN-NEXT: stp xzr, xzr, [x{{[0-9]+}}, #16]
 ; CHECK-NEXT: ret
 entry:
   store i64 0, i64* %p