[mips] Make sure loads from lazy-binding entries do not get CSE'd or hoisted out
of loops.
Previously, two consecutive calls to function "func" would result in the
following sequence of instructions:
1. load $16, %got(func)($gp) // load address of lazy-binding stub.
2. move $25, $16
3. jalr $25 // jump to lazy-binding stub.
4. nop
5. move $25, $16
6. jalr $25 // jump to lazy-binding stub again.
With this patch, the second call directly jumps to func's address, bypassing
the lazy-binding resolution routine:
1. load $25, %got(func)($gp) // load address of lazy-binding stub.
2. jalr $25 // jump to lazy-binding stub.
3. nop
4. load $25, %got(func)($gp) // load resolved address of func.
5. jalr $25 // directly jump to func.
llvm-svn: 191591
diff --git a/llvm/lib/Target/Mips/MipsDelaySlotFiller.cpp b/llvm/lib/Target/Mips/MipsDelaySlotFiller.cpp
index 545a38d..34286db 100644
--- a/llvm/lib/Target/Mips/MipsDelaySlotFiller.cpp
+++ b/llvm/lib/Target/Mips/MipsDelaySlotFiller.cpp
@@ -421,8 +421,7 @@
return false;
if (const PseudoSourceValue *PSV = dyn_cast<const PseudoSourceValue>(V))
- return !PSV->PseudoSourceValue::isConstant(0) &&
- (V != PseudoSourceValue::getStack());
+ return !PSV->isConstant(0) && V != PseudoSourceValue::getStack();
return true;
}