[ARMv8] Prevent generation of deprecated IT blocks on ARMv8 in Thumb mode.
IT blocks can only be one instruction lonf, and can only contain a subset of
the 16 instructions.
Patch by Artyom Skrobov!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190309 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/IfConversion.cpp b/lib/CodeGen/IfConversion.cpp
index 1ae7e3b..418994d 100644
--- a/lib/CodeGen/IfConversion.cpp
+++ b/lib/CodeGen/IfConversion.cpp
@@ -666,32 +666,29 @@
bool isPredicated = TII->isPredicated(I);
bool isCondBr = BBI.IsBrAnalyzable && I->isConditionalBranch();
- if (!isCondBr) {
- if (!isPredicated) {
- BBI.NonPredSize++;
- unsigned ExtraPredCost = 0;
- unsigned NumCycles = TII->getInstrLatency(InstrItins, &*I,
- &ExtraPredCost);
- if (NumCycles > 1)
- BBI.ExtraCost += NumCycles-1;
- BBI.ExtraCost2 += ExtraPredCost;
- } else if (!AlreadyPredicated) {
- // FIXME: This instruction is already predicated before the
- // if-conversion pass. It's probably something like a conditional move.
- // Mark this block unpredicable for now.
- BBI.IsUnpredicable = true;
- return;
- }
+ // A conditional branch is not predicable, but it may be eliminated.
+ if (isCondBr)
+ continue;
+
+ if (!isPredicated) {
+ BBI.NonPredSize++;
+ unsigned ExtraPredCost = 0;
+ unsigned NumCycles = TII->getInstrLatency(InstrItins, &*I,
+ &ExtraPredCost);
+ if (NumCycles > 1)
+ BBI.ExtraCost += NumCycles-1;
+ BBI.ExtraCost2 += ExtraPredCost;
+ } else if (!AlreadyPredicated) {
+ // FIXME: This instruction is already predicated before the
+ // if-conversion pass. It's probably something like a conditional move.
+ // Mark this block unpredicable for now.
+ BBI.IsUnpredicable = true;
+ return;
}
if (BBI.ClobbersPred && !isPredicated) {
// Predicate modification instruction should end the block (except for
// already predicated instructions and end of block branches).
- if (isCondBr) {
- // A conditional branch is not predicable, but it may be eliminated.
- continue;
- }
-
// Predicate may have been modified, the subsequent (currently)
// unpredicated instructions cannot be correctly predicated.
BBI.IsUnpredicable = true;