From: Craig Topper <craig.topper@gmail.com>
Date: Mon, 27 Feb 2017 16:15:27 +0000 (+0000)
Subject: [X86] Fix SmallVector sizes in constant pool shuffle decoding to avoid heap allocation
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=72dbe0cc0e5240838584487791a812107f4c8f3e;p=llvm

[X86] Fix SmallVector sizes in constant pool shuffle decoding to avoid heap allocation

Some of the vectors are under sized to avoid heap allocation. In one case the vector was oversized.

Differential Revision: https://reviews.llvm.org/D30387

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296353 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Target/X86/X86ShuffleDecodeConstantPool.cpp b/lib/Target/X86/X86ShuffleDecodeConstantPool.cpp
index 3ce8609267f..df6ddafa717 100644
--- a/lib/Target/X86/X86ShuffleDecodeConstantPool.cpp
+++ b/lib/Target/X86/X86ShuffleDecodeConstantPool.cpp
@@ -104,7 +104,7 @@ void DecodePSHUFBMask(const Constant *C, SmallVectorImpl<int> &ShuffleMask) {
 
   // The shuffle mask requires a byte vector.
   APInt UndefElts;
-  SmallVector<uint64_t, 32> RawMask;
+  SmallVector<uint64_t, 64> RawMask;
   if (!extractConstantMask(C, 8, UndefElts, RawMask))
     return;
 
@@ -145,7 +145,7 @@ void DecodeVPERMILPMask(const Constant *C, unsigned ElSize,
 
   // The shuffle mask requires elements the same size as the target.
   APInt UndefElts;
-  SmallVector<uint64_t, 8> RawMask;
+  SmallVector<uint64_t, 16> RawMask;
   if (!extractConstantMask(C, ElSize, UndefElts, RawMask))
     return;
 
@@ -231,7 +231,7 @@ void DecodeVPPERMMask(const Constant *C, SmallVectorImpl<int> &ShuffleMask) {
 
   // The shuffle mask requires a byte vector.
   APInt UndefElts;
-  SmallVector<uint64_t, 32> RawMask;
+  SmallVector<uint64_t, 16> RawMask;
   if (!extractConstantMask(C, 8, UndefElts, RawMask))
     return;
 
@@ -286,7 +286,7 @@ void DecodeVPERMVMask(const Constant *C, unsigned ElSize,
 
   // The shuffle mask requires elements the same size as the target.
   APInt UndefElts;
-  SmallVector<uint64_t, 8> RawMask;
+  SmallVector<uint64_t, 64> RawMask;
   if (!extractConstantMask(C, ElSize, UndefElts, RawMask))
     return;
 
@@ -314,7 +314,7 @@ void DecodeVPERMV3Mask(const Constant *C, unsigned ElSize,
 
   // The shuffle mask requires elements the same size as the target.
   APInt UndefElts;
-  SmallVector<uint64_t, 8> RawMask;
+  SmallVector<uint64_t, 64> RawMask;
   if (!extractConstantMask(C, ElSize, UndefElts, RawMask))
     return;