Try both ways to fold an add together. This allows us to generate this code
imul %EAX, %EAX, 400
add %ECX, %EAX
add %ESI, DWORD PTR [%ECX + 4*%EDX]
inc %EDX
cmp %EDX, 100
instead of this:
imul %EAX, %EAX, 400
add %ECX, %EAX
mov %EAX, %EDX
shl %EAX, 2
add %ECX, %EAX
add %ESI, DWORD PTR [%ECX]
inc %EDX
cmp %EDX, 100
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@19513 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86ISelPattern.cpp b/lib/Target/X86/X86ISelPattern.cpp
index b3a93b1..194c2fa 100644
--- a/lib/Target/X86/X86ISelPattern.cpp
+++ b/lib/Target/X86/X86ISelPattern.cpp
@@ -527,6 +527,10 @@
!SelectAddress(N.Val->getOperand(1), AM))
return false;
AM = Backup;
+ if (!SelectAddress(N.Val->getOperand(1), AM) &&
+ !SelectAddress(N.Val->getOperand(0), AM))
+ return false;
+ AM = Backup;
break;
}
}