14 // complex alignment assumptions that apply to vector loads and stores that
19 #define AA_NAME "alignment-from-assumptions"
41   "Number of loads changed by alignment assumptions");
43   "Number of stores changed by alignment assumptions");
45   "Number of memory intrinsics changed by alignment assumptions");
74 static const char aip_name[] = "Alignment from assumptions";
87 // Given an expression for the (constant) alignment, AlignSCEV, and an
89 // DiffSCEV, compute the alignment of the displaced pointer if it can be reduced
90 // to a constant. Using SCEV to compute alignment handles the case where
96   // DiffUnits = Diff % int64_t(Alignment)  in getNewAlignmentDiff()
108     // If the displacement is an exact multiple of the alignment, then the  in getNewAlignmentDiff()
109     // displaced pointer has the same alignment as the aligned pointer, so  in getNewAlignmentDiff()
110     // return the alignment value.  in getNewAlignmentDiff()
126 // alignment AlignSCEV. Use that information, if possible, to compute a new
127 // alignment for Ptr.
142   DEBUG(dbgs() << "AFI: alignment of " << *Ptr << " relative to " <<  in getNewAlignment()
147   DEBUG(dbgs() << "\tnew alignment: " << NewAlignment << "\n");  in getNewAlignment()
153     // The relative offset to the alignment assumption did not yield a constant,  in getNewAlignment()
156     // 32-byte aligned, but instead alternate between 32 and 16-byte alignment.  in getNewAlignment()
157     // As a result, the new alignment will not be a constant, but can still  in getNewAlignment()
163     DEBUG(dbgs() << "\ttrying start/inc alignment using start " <<  in getNewAlignment()
166     // Now compute the new alignment using the displacement to the value in the  in getNewAlignment()
167     // first iteration, and also the alignment using the per-iteration delta.  in getNewAlignment()
173     DEBUG(dbgs() << "\tnew start alignment: " << NewAlignment << "\n");  in getNewAlignment()
174     DEBUG(dbgs() << "\tnew inc alignment: " << NewIncAlignment << "\n");  in getNewAlignment()
180         DEBUG(dbgs() << "\tnew start/inc alignment: " <<  in getNewAlignment()
186         DEBUG(dbgs() << "\tnew start/inc alignment: " <<  in getNewAlignment()
191       DEBUG(dbgs() << "\tnew start/inc alignment: " <<  in getNewAlignment()
204   // An alignment assume must be a statement about the least-significant  in extractAlignmentInfo()
244   // trivial and tells us nothing about the alignment of the left operand).  in extractAlignmentInfo()
249   // Cap the alignment at the maximum with which LLVM can deal (and make sure  in extractAlignmentInfo()
251   uint64_t Alignment;  in extractAlignmentInfo()  local
254   Alignment = std::min(1u << TrailingOnes, +Value::MaximumAlignment);  in extractAlignmentInfo()
257   AlignSCEV = SE->getConstant(Int64Ty, Alignment);  in extractAlignmentInfo()
337       // For memory transfers, we need a common alignment for both the  in processAssumption()
338       // source and destination. If we have a new alignment for this  in processAssumption()
341       // change the alignment at that point.  in processAssumption()