From 3b4b5367da29a1598dc333acf37652ef286e9225 Mon Sep 17 00:00:00 2001
From: David Majnemer <david.majnemer@gmail.com>
Date: Wed, 22 May 2013 08:13:02 +0000
Subject: X86: Remove test instructions proceeding shift by immediate
 instructions

Allow LLVM to take advantage of shift instructions that set the ZF flag,
making instructions that test the destination superfluous.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182454 91177308-0d34-0410-b5e6-96231b3b80d8
---
 test/CodeGen/X86/peep-test-4.ll | 37 +++++++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)

(limited to 'test/CodeGen/X86/peep-test-4.ll')

diff --git a/test/CodeGen/X86/peep-test-4.ll b/test/CodeGen/X86/peep-test-4.ll
index b670c31..a1eea00 100644
--- a/test/CodeGen/X86/peep-test-4.ll
+++ b/test/CodeGen/X86/peep-test-4.ll
@@ -1,5 +1,6 @@
 ; RUN: llc < %s -mtriple=x86_64-pc-linux -mattr=+bmi,+bmi2,+popcnt | FileCheck %s
 declare void @foo(i32)
+declare void @foo64(i64)
 
 ; CHECK: neg:
 ; CHECK: negl %edi
@@ -55,6 +56,24 @@ return:
   ret void
 }
 
+; CHECK: shri:
+; CHECK: shrl $3, %edi
+; CHECK-NEXT: je
+; CHECK: jmp foo
+; CHECK: ret
+define void @shri(i32 %x) nounwind {
+  %ashr = lshr i32 %x, 3
+  %cmp = icmp eq i32 %ashr, 0
+  br i1 %cmp, label %return, label %bb
+
+bb:
+  tail call void @foo(i32 %ashr)
+  br label %return
+
+return:
+  ret void
+}
+
 ; CHECK: shl:
 ; CHECK: addl %edi, %edi
 ; CHECK-NEXT: je
@@ -73,6 +92,24 @@ return:
   ret void
 }
 
+; CHECK: shli:
+; CHECK: shll $4, %edi
+; CHECK-NEXT: je
+; CHECK: jmp foo
+; CHECK: ret
+define void @shli(i32 %x) nounwind {
+  %shl = shl i32 %x, 4
+  %cmp = icmp eq i32 %shl, 0
+  br i1 %cmp, label %return, label %bb
+
+bb:
+  tail call void @foo(i32 %shl)
+  br label %return
+
+return:
+  ret void
+}
+
 ; CHECK: adc:
 ; CHECK: movabsq $-9223372036854775808, %rax
 ; CHECK-NEXT: addq  %rdi, %rax
-- 
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