fix an x86 fast isel issue where we'd completely give up on folding an address
when we have a global variable base an an index. Instead, just give up on
folding the global variable.
Before we'd geenrate:
_test: ## @test
## BB#0:
movq _rtx_length@GOTPCREL(%rip), %rax
leaq (%rax), %rax
addq %rdi, %rax
movzbl (%rax), %eax
ret
now we generate:
_test: ## @test
## BB#0:
movq _rtx_length@GOTPCREL(%rip), %rax
movzbl (%rax,%rdi), %eax
ret
The difference is even more significant when there is a scale
involved.
This fixes rdar://9289558 - total fail with addr mode formation at -O0/x86-64
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129664 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/CodeGen/X86/fast-isel-x86-64.ll b/test/CodeGen/X86/fast-isel-x86-64.ll
index c0815aa..e98c473 100644
--- a/test/CodeGen/X86/fast-isel-x86-64.ll
+++ b/test/CodeGen/X86/fast-isel-x86-64.ll
@@ -28,11 +28,11 @@
if.end: ; preds = %if.then, %entry
ret void
-}
-
; CHECK: test2:
; CHECK: movq %rdi, -8(%rsp)
; CHECK: cmpq $42, -8(%rsp)
+}
+
@@ -40,8 +40,24 @@
define i64 @test3() nounwind {
%A = ptrtoint i32* @G to i64
ret i64 %A
-}
-
; CHECK: test3:
; CHECK: movq _G@GOTPCREL(%rip), %rax
; CHECK-NEXT: ret
+}
+
+
+
+; rdar://9289558
+@rtx_length = external global [153 x i8]
+
+define i32 @test4(i64 %idxprom9) nounwind {
+ %arrayidx10 = getelementptr inbounds [153 x i8]* @rtx_length, i32 0, i64 %idxprom9
+ %tmp11 = load i8* %arrayidx10, align 1
+ %conv = zext i8 %tmp11 to i32
+ ret i32 %conv
+
+; CHECK: test4:
+; CHECK: movq _rtx_length@GOTPCREL(%rip), %rax
+; CHECK-NEXT: movzbl (%rax,%rdi), %eax
+; CHECK-NEXT: ret
+}