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-rw-r--r--llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp1
-rw-r--r--llvm/lib/Target/AArch64/AArch64FrameLowering.cpp3
-rw-r--r--llvm/lib/Target/AArch64/AArch64InstrInfo.td13
-rw-r--r--llvm/lib/Target/AArch64/AArch64RegisterInfo.td6
4 files changed, 21 insertions, 2 deletions
diff --git a/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp b/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
index 469c9c27ec4..23b6a65555a 100644
--- a/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
+++ b/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
@@ -591,6 +591,7 @@ void AArch64AsmPrinter::EmitInstruction(const MachineInstr *MI) {
// attributes (isCall, isReturn, etc.). We lower them to the real
// instruction here.
case AArch64::TCRETURNri:
+ case AArch64::TCRETURNriBTI:
case AArch64::TCRETURNriALL: {
MCInst TmpInst;
TmpInst.setOpcode(AArch64::BR);
diff --git a/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp b/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp
index f2d7ea9ba3e..b0451ca2edb 100644
--- a/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp
+++ b/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp
@@ -927,7 +927,8 @@ void AArch64FrameLowering::emitEpilogue(MachineFunction &MF,
DL = MBBI->getDebugLoc();
unsigned RetOpcode = MBBI->getOpcode();
IsTailCallReturn = RetOpcode == AArch64::TCRETURNdi ||
- RetOpcode == AArch64::TCRETURNri;
+ RetOpcode == AArch64::TCRETURNri ||
+ RetOpcode == AArch64::TCRETURNriBTI;
}
int NumBytes = MFI.getStackSize();
const AArch64FunctionInfo *AFI = MF.getInfo<AArch64FunctionInfo>();
diff --git a/llvm/lib/Target/AArch64/AArch64InstrInfo.td b/llvm/lib/Target/AArch64/AArch64InstrInfo.td
index 3531d1e1622..1d9e3d0b812 100644
--- a/llvm/lib/Target/AArch64/AArch64InstrInfo.td
+++ b/llvm/lib/Target/AArch64/AArch64InstrInfo.td
@@ -360,6 +360,9 @@ let RecomputePerFunction = 1 in {
def NotForCodeSize : Predicate<"!MF->getFunction().optForSize()">;
// Avoid generating STRQro if it is slow, unless we're optimizing for code size.
def UseSTRQro : Predicate<"!Subtarget->isSTRQroSlow() || MF->getFunction().optForSize()">;
+
+ def UseBTI : Predicate<[{ MF->getFunction().hasFnAttribute("branch-target-enforcement") }]>;
+ def NotUseBTI : Predicate<[{ !MF->getFunction().hasFnAttribute("branch-target-enforcement") }]>;
}
include "AArch64InstrFormats.td"
@@ -6641,10 +6644,18 @@ let isCall = 1, isTerminator = 1, isReturn = 1, isBarrier = 1, Uses = [SP] in {
// some verifier checks for outlined functions.
def TCRETURNriALL : Pseudo<(outs), (ins GPR64:$dst, i32imm:$FPDiff), []>,
Sched<[WriteBrReg]>;
+ // Indirect tail-call limited to only use registers (x16 and x17) which are
+ // allowed to tail-call a "BTI c" instruction.
+ def TCRETURNriBTI : Pseudo<(outs), (ins rtcGPR64:$dst, i32imm:$FPDiff), []>,
+ Sched<[WriteBrReg]>;
}
def : Pat<(AArch64tcret tcGPR64:$dst, (i32 timm:$FPDiff)),
- (TCRETURNri tcGPR64:$dst, imm:$FPDiff)>;
+ (TCRETURNri tcGPR64:$dst, imm:$FPDiff)>,
+ Requires<[NotUseBTI]>;
+def : Pat<(AArch64tcret rtcGPR64:$dst, (i32 timm:$FPDiff)),
+ (TCRETURNriBTI rtcGPR64:$dst, imm:$FPDiff)>,
+ Requires<[UseBTI]>;
def : Pat<(AArch64tcret tglobaladdr:$dst, (i32 timm:$FPDiff)),
(TCRETURNdi texternalsym:$dst, imm:$FPDiff)>;
def : Pat<(AArch64tcret texternalsym:$dst, (i32 timm:$FPDiff)),
diff --git a/llvm/lib/Target/AArch64/AArch64RegisterInfo.td b/llvm/lib/Target/AArch64/AArch64RegisterInfo.td
index bbf401b474c..d3710cea068 100644
--- a/llvm/lib/Target/AArch64/AArch64RegisterInfo.td
+++ b/llvm/lib/Target/AArch64/AArch64RegisterInfo.td
@@ -200,6 +200,12 @@ def tcGPR64 : RegisterClass<"AArch64", [i64], 64, (sub GPR64common, X19, X20, X2
X22, X23, X24, X25, X26,
X27, X28, FP, LR)>;
+// Restricted set of tail call registers, for use when branch target
+// enforcement is enabled. These are the only registers which can be used to
+// indirectly branch (not call) to the "BTI c" instruction at the start of a
+// BTI-protected function.
+def rtcGPR64 : RegisterClass<"AArch64", [i64], 64, (add X16, X17)>;
+
// GPR register classes for post increment amount of vector load/store that
// has alternate printing when Rm=31 and prints a constant immediate value
// equal to the total number of bytes transferred.
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