Factor out the code for sign-extending/truncating gep indices

and use it in x86 address mode folding. Also, make
getRegForValue return 0 for illegal types even if it has a
ValueMap for them, because Argument values are put in the
ValueMap. This fixes PR3181.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60696 91177308-0d34-0410-b5e6-96231b3b80d8

test/CodeGen/X86/fast-isel-gep-sext.ll

@@ -0,0 +1,17 @@
+; RUN: llvm-as < %s | llc -march=x86-64 -fast | grep movslq
+; RUN: llvm-as < %s | llc -march=x86 -fast
+; PR3181
+
+; GEP indices are interpreted as signed integers, so they
+; should be sign-extended to 64 bits on 64-bit targets.
+
+define i32 @foo(i32 %t3, i32* %t1) nounwind {
+       %t9 = getelementptr i32* %t1, i32 %t3           ; <i32*> [#uses=1]
+       %t15 = load i32* %t9            ; <i32> [#uses=1]
+       ret i32 %t15
+}
+define i32 @bar(i64 %t3, i32* %t1) nounwind {
+       %t9 = getelementptr i32* %t1, i64 %t3           ; <i32*> [#uses=1]
+       %t15 = load i32* %t9            ; <i32> [#uses=1]
+       ret i32 %t15
+}