cl::desc("A flag that overrides the target's max unroll factor for "
"vectorized loops."));
+static cl::opt<unsigned> ForceTargetInstructionCost(
+ "force-target-instruction-cost", cl::init(0), cl::Hidden,
+ cl::desc("A flag that overrides the target's expected cost for "
+ "an instruction to a single constant value. Mostly "
+ "useful for getting consistent testing."));
+
static cl::opt<unsigned> SmallLoopCost(
"small-loop-cost", cl::init(20), cl::Hidden,
cl::desc("The cost of a loop that is considered 'small' by the unroller."));
continue;
unsigned C = getInstructionCost(it, VF);
+
+ // Check if we should override the cost.
+ if (ForceTargetInstructionCost.getNumOccurrences() > 0)
+ C = ForceTargetInstructionCost;
+
BlockCost += C;
DEBUG(dbgs() << "LV: Found an estimated cost of " << C << " for VF " <<
VF << " For instruction: " << *it << '\n');
-; RUN: opt < %s -loop-vectorize -force-vector-width=1 -force-target-num-scalar-regs=16 -force-target-max-scalar-unroll=8 -small-loop-cost=20 -dce -instcombine -S | FileCheck %s
+; RUN: opt < %s -loop-vectorize -force-vector-width=1 -force-target-num-scalar-regs=16 -force-target-max-scalar-unroll=8 -force-target-instruction-cost=1 -small-loop-cost=40 -dce -instcombine -S | FileCheck %s
target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
target triple = "x86_64-apple-macosx10.8.0"