This updates check for double precision zero floating point constant to allow
use of instruction with immediate value rather than temporary register.
Currently "a == 0.0", where "a" is of "double" type generates:
vmov.i32 d16, #0x0
vcmpe.f64 d0, d16
With this change it becomes:
vcmpe.f64 d0, #0
Patch by Sergey Dmitrouk.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220486
91177308-0d34-0410-b5e6-
96231b3b80d8
if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CP->getConstVal()))
return CFP->getValueAPF().isPosZero();
}
+ } else if (Op->getOpcode() == ISD::BITCAST &&
+ Op->getValueType(0) == MVT::f64) {
+ // Handle (ISD::BITCAST (ARMISD::VMOVIMM (ISD::TargetConstant 0)) MVT::f64)
+ // created by LowerConstantFP().
+ SDValue BitcastOp = Op->getOperand(0);
+ if (BitcastOp->getOpcode() == ARMISD::VMOVIMM) {
+ SDValue MoveOp = BitcastOp->getOperand(0);
+ if (MoveOp->getOpcode() == ISD::TargetConstant &&
+ cast<ConstantSDNode>(MoveOp)->getZExtValue() == 0) {
+ return true;
+ }
+ }
}
return false;
}
--- /dev/null
+; RUN: llc -mtriple=linux-arm-gnueabihf -mattr=+neon %s -o - | FileCheck %s
+
+; Check that no intermediate integer register is used.
+define i32 @no-intermediate-register-for-zero-imm(double %x) #0 {
+entry:
+; CHECK-LABEL: no-intermediate-register-for-zero-imm
+; CHECK-NOT: vmov
+; CHECK: vcmp
+ %cmp = fcmp une double %x, 0.000000e+00
+ %conv = zext i1 %cmp to i32
+ ret i32 %conv
+}