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-rw-r--r--llvm/lib/Target/Mips/MipsConstantIslandPass.cpp156
-rw-r--r--llvm/lib/Target/Mips/MipsSubtarget.cpp6
2 files changed, 157 insertions, 5 deletions
diff --git a/llvm/lib/Target/Mips/MipsConstantIslandPass.cpp b/llvm/lib/Target/Mips/MipsConstantIslandPass.cpp
index 7ab601c1a1a..3c62baeec15 100644
--- a/llvm/lib/Target/Mips/MipsConstantIslandPass.cpp
+++ b/llvm/lib/Target/Mips/MipsConstantIslandPass.cpp
@@ -77,6 +77,103 @@ static cl::opt<bool> NoLoadRelaxation(
cl::desc("Don't relax loads to long loads - for testing purposes"),
cl::Hidden);
+static unsigned int branchTargetOperand(MachineInstr *MI) {
+ switch (MI->getOpcode()) {
+ case Mips::Bimm16:
+ case Mips::BimmX16:
+ case Mips::Bteqz16:
+ case Mips::BteqzX16:
+ case Mips::Btnez16:
+ case Mips::BtnezX16:
+ case Mips::Jal16:
+ return 0;
+ case Mips::BeqzRxImm16:
+ case Mips::BeqzRxImmX16:
+ case Mips::BnezRxImm16:
+ case Mips::BnezRxImmX16:
+ return 1;
+ }
+ llvm_unreachable("Unknown branch type");
+}
+
+static unsigned int longformBranchOpcode(unsigned int Opcode) {
+ switch (Opcode) {
+ case Mips::Bimm16:
+ case Mips::BimmX16:
+ return Mips::BimmX16;
+ case Mips::Bteqz16:
+ case Mips::BteqzX16:
+ return Mips::BteqzX16;
+ case Mips::Btnez16:
+ case Mips::BtnezX16:
+ return Mips::BtnezX16;
+ case Mips::Jal16:
+ return Mips::Jal16;
+ case Mips::BeqzRxImm16:
+ case Mips::BeqzRxImmX16:
+ return Mips::BeqzRxImmX16;
+ case Mips::BnezRxImm16:
+ case Mips::BnezRxImmX16:
+ return Mips::BnezRxImmX16;
+ }
+ llvm_unreachable("Unknown branch type");
+}
+
+//
+// FIXME: need to go through this whole constant islands port and check the math
+// for branch ranges and clean this up and make some functions to calculate things
+// that are done many times identically.
+// Need to refactor some of the code to call this routine.
+//
+static unsigned int branchMaxOffsets(unsigned int Opcode) {
+ unsigned Bits, Scale;
+ switch (Opcode) {
+ case Mips::Bimm16:
+ Bits = 11;
+ Scale = 2;
+ break;
+ case Mips::BimmX16:
+ Bits = 16;
+ Scale = 2;
+ break;
+ case Mips::BeqzRxImm16:
+ Bits = 8;
+ Scale = 2;
+ break;
+ case Mips::BeqzRxImmX16:
+ Bits = 16;
+ Scale = 2;
+ break;
+ case Mips::BnezRxImm16:
+ Bits = 8;
+ Scale = 2;
+ break;
+ case Mips::BnezRxImmX16:
+ Bits = 16;
+ Scale = 2;
+ break;
+ case Mips::Bteqz16:
+ Bits = 8;
+ Scale = 2;
+ break;
+ case Mips::BteqzX16:
+ Bits = 16;
+ Scale = 2;
+ break;
+ case Mips::Btnez16:
+ Bits = 8;
+ Scale = 2;
+ break;
+ case Mips::BtnezX16:
+ Bits = 16;
+ Scale = 2;
+ break;
+ default:
+ llvm_unreachable("Unknown branch type");
+ }
+ unsigned MaxOffs = ((1 << (Bits-1))-1) * Scale;
+ return MaxOffs;
+}
namespace {
@@ -603,6 +700,47 @@ initializeFunctionInfo(const std::vector<MachineInstr*> &CPEMIs) {
Bits = 16;
Scale = 2;
isCond = false;
+ break;
+ case Mips::BeqzRxImm16:
+ Bits = 8;
+ Scale = 2;
+ isCond = true;
+ break;
+ case Mips::BeqzRxImmX16:
+ Bits = 16;
+ Scale = 2;
+ isCond = true;
+ break;
+ case Mips::BnezRxImm16:
+ Bits = 8;
+ Scale = 2;
+ isCond = true;
+ break;
+ case Mips::BnezRxImmX16:
+ Bits = 16;
+ Scale = 2;
+ isCond = true;
+ break;
+ case Mips::Bteqz16:
+ Bits = 8;
+ Scale = 2;
+ isCond = true;
+ break;
+ case Mips::BteqzX16:
+ Bits = 16;
+ Scale = 2;
+ isCond = true;
+ break;
+ case Mips::Btnez16:
+ Bits = 8;
+ Scale = 2;
+ isCond = true;
+ break;
+ case Mips::BtnezX16:
+ Bits = 16;
+ Scale = 2;
+ isCond = true;
+ break;
}
// Record this immediate branch.
unsigned MaxOffs = ((1 << (Bits-1))-1) * Scale;
@@ -1382,7 +1520,8 @@ unsigned PCAdj = 4;
/// away to fit in its displacement field.
bool MipsConstantIslands::fixupImmediateBr(ImmBranch &Br) {
MachineInstr *MI = Br.MI;
- MachineBasicBlock *DestBB = MI->getOperand(0).getMBB();
+ unsigned TargetOperand = branchTargetOperand(MI);
+ MachineBasicBlock *DestBB = MI->getOperand(TargetOperand).getMBB();
// Check to see if the DestBB is already in-range.
if (isBBInRange(MI, DestBB, Br.MaxDisp))
@@ -1434,13 +1573,26 @@ MipsConstantIslands::fixupUnconditionalBr(ImmBranch &Br) {
return true;
}
+
/// fixupConditionalBr - Fix up a conditional branch whose destination is too
/// far away to fit in its displacement field. It is converted to an inverse
/// conditional branch + an unconditional branch to the destination.
bool
MipsConstantIslands::fixupConditionalBr(ImmBranch &Br) {
MachineInstr *MI = Br.MI;
- MachineBasicBlock *DestBB = MI->getOperand(0).getMBB();
+ unsigned TargetOperand = branchTargetOperand(MI);
+ MachineBasicBlock *DestBB = MI->getOperand(TargetOperand).getMBB();
+ unsigned Opcode = MI->getOpcode();
+ unsigned LongFormOpcode = longformBranchOpcode(Opcode);
+ unsigned LongFormMaxOff = branchMaxOffsets(LongFormOpcode);
+
+ // Check to see if the DestBB is already in-range.
+ if (isBBInRange(MI, DestBB, LongFormMaxOff)) {
+ Br.MaxDisp = LongFormMaxOff;
+ MI->setDesc(TII->get(LongFormOpcode));
+ return true;
+ }
+ llvm_unreachable("Fixup of very long conditional branch not working yet.");
// Add an unconditional branch to the destination and invert the branch
// condition to jump over it:
diff --git a/llvm/lib/Target/Mips/MipsSubtarget.cpp b/llvm/lib/Target/Mips/MipsSubtarget.cpp
index 9688f0e264b..5103084db5b 100644
--- a/llvm/lib/Target/Mips/MipsSubtarget.cpp
+++ b/llvm/lib/Target/Mips/MipsSubtarget.cpp
@@ -55,9 +55,9 @@ Mips16HardFloat("mips16-hard-float", cl::NotHidden,
static cl::opt<bool>
Mips16ConstantIslands(
- "mips16-constant-islands", cl::Hidden,
- cl::desc("MIPS: mips16 constant islands enable. experimental feature"),
- cl::init(false));
+ "mips16-constant-islands", cl::NotHidden,
+ cl::desc("MIPS: mips16 constant islands enable."),
+ cl::init(true));
void MipsSubtarget::anchor() { }
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