From af70e5c676140a55ec619f552c8fd76b7edf3c6d Mon Sep 17 00:00:00 2001
From: Dan Gohman <gohman@apple.com>
Date: Wed, 26 Aug 2009 14:59:13 +0000
Subject: Don't use INSERT_SUBREG to model anyext operations on x86-64, as it
 leads to partial-register definitions. To help avoid redundant
 zero-extensions, also teach the h-register matching patterns that use movzbl
 to match anyext as well as zext.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@80099 91177308-0d34-0410-b5e6-96231b3b80d8
---
 test/CodeGen/X86/anyext.ll | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)
 create mode 100644 test/CodeGen/X86/anyext.ll

(limited to 'test/CodeGen/X86/anyext.ll')

diff --git a/test/CodeGen/X86/anyext.ll b/test/CodeGen/X86/anyext.ll
new file mode 100644
index 0000000000..c5f03abee7
--- /dev/null
+++ b/test/CodeGen/X86/anyext.ll
@@ -0,0 +1,18 @@
+; RUN: llvm-as < %s | llc -march=x86-64 | grep movzbl | count 2
+
+; Use movzbl to avoid partial-register updates.
+
+define i32 @foo(i32 %p, i8 zeroext %x) nounwind {
+  %q = trunc i32 %p to i8
+  %r = udiv i8 %q, %x
+  %s = zext i8 %r to i32
+  %t = and i32 %s, 1
+  ret i32 %t
+}
+define i32 @bar(i32 %p, i16 zeroext %x) nounwind {
+  %q = trunc i32 %p to i16
+  %r = udiv i16 %q, %x
+  %s = zext i16 %r to i32
+  %t = and i32 %s, 1
+  ret i32 %t
+}
-- 
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