[llvm] r284071 - GlobalISel: select G_BRCOND instructions on AArch64.
Tim Northover via llvm-commits
llvm-commits at lists.llvm.org
Wed Oct 12 15:49:01 PDT 2016
Author: tnorthover
Date: Wed Oct 12 17:49:01 2016
New Revision: 284071
URL: http://llvm.org/viewvc/llvm-project?rev=284071&view=rev
Log:
GlobalISel: select G_BRCOND instructions on AArch64.
Modified:
llvm/trunk/lib/Target/AArch64/AArch64InstructionSelector.cpp
llvm/trunk/test/CodeGen/AArch64/GlobalISel/arm64-instructionselect.mir
Modified: llvm/trunk/lib/Target/AArch64/AArch64InstructionSelector.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/AArch64/AArch64InstructionSelector.cpp?rev=284071&r1=284070&r2=284071&view=diff
==============================================================================
--- llvm/trunk/lib/Target/AArch64/AArch64InstructionSelector.cpp (original)
+++ llvm/trunk/lib/Target/AArch64/AArch64InstructionSelector.cpp Wed Oct 12 17:49:01 2016
@@ -299,6 +299,28 @@ bool AArch64InstructionSelector::select(
return true;
}
+ case TargetOpcode::G_BRCOND: {
+ if (Ty.getSizeInBits() > 32) {
+ // We shouldn't need this on AArch64, but it would be implemented as an
+ // EXTRACT_SUBREG followed by a TBNZW because TBNZX has no encoding if the
+ // bit being tested is < 32.
+ DEBUG(dbgs() << "G_BRCOND has type: " << Ty
+ << ", expected at most 32-bits");
+ return false;
+ }
+
+ const unsigned CondReg = I.getOperand(0).getReg();
+ MachineBasicBlock *DestMBB = I.getOperand(1).getMBB();
+
+ auto MIB = BuildMI(MBB, I, I.getDebugLoc(), TII.get(AArch64::TBNZW))
+ .addUse(CondReg)
+ .addImm(/*bit offset=*/0)
+ .addMBB(DestMBB);
+
+ I.eraseFromParent();
+ return constrainSelectedInstRegOperands(*MIB.getInstr(), TII, TRI, RBI);
+ }
+
case TargetOpcode::G_CONSTANT: {
if (Ty.getSizeInBits() <= 32)
I.setDesc(TII.get(AArch64::MOVi32imm));
Modified: llvm/trunk/test/CodeGen/AArch64/GlobalISel/arm64-instructionselect.mir
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AArch64/GlobalISel/arm64-instructionselect.mir?rev=284071&r1=284070&r2=284071&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/AArch64/GlobalISel/arm64-instructionselect.mir (original)
+++ llvm/trunk/test/CodeGen/AArch64/GlobalISel/arm64-instructionselect.mir Wed Oct 12 17:49:01 2016
@@ -54,6 +54,7 @@
define void @fdiv_s64_gpr() { ret void }
define void @unconditional_br() { ret void }
+ define void @conditional_br() { ret void }
define void @load_s64_gpr(i64* %addr) { ret void }
define void @load_s32_gpr(i32* %addr) { ret void }
@@ -1013,6 +1014,29 @@ body: |
...
---
+# CHECK-LABEL: name: conditional_br
+name: conditional_br
+legalized: true
+regBankSelected: true
+
+registers:
+ - { id: 0, class: gpr }
+
+# CHECK: body:
+# CHECK: bb.0:
+# CHECK: TBNZW %0, 0, %bb.1
+# CHECK: B %bb.0
+body: |
+ bb.0:
+ successors: %bb.0, %bb.1
+ %0(s1) = COPY %w0
+ G_BRCOND %0(s1), %bb.1
+ G_BR %bb.0
+
+ bb.1:
+...
+
+---
# CHECK-LABEL: name: load_s64_gpr
name: load_s64_gpr
legalized: true
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