MC/X86: Implement custom lowering to make sure we match things like

  X86::ADC32ri $0, %eax
to
  X86::ADC32i32 $0

llvm-svn: 104030

1 files changed, 26 insertions, 0 deletions

diff --git a/llvm/test/CodeGen/X86/mcinst-lowering.ll b/llvm/test/CodeGen/X86/mcinst-lowering.ll
new file mode 100644
index 00000000000..1ef5a971bab
--- /dev/null
+++ b/llvm/test/CodeGen/X86/mcinst-lowering.ll
@@ -0,0 +1,26 @@
+; RUN: llc --show-mc-encoding < %s | FileCheck %s
+
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64"
+target triple = "x86_64-apple-darwin10.0.0"
+
+define i32 @f0(i32* nocapture %x) nounwind readonly ssp {
+entry:
+  %tmp1 = load i32* %x                            ; <i32> [#uses=2]
+  %tobool = icmp eq i32 %tmp1, 0                  ; <i1> [#uses=1]
+  br i1 %tobool, label %if.end, label %return
+
+if.end:                                           ; preds = %entry
+
+; Check that we lower to the short form of cmpl, which has a fixed %eax
+; register.
+;
+; CHECK: cmpl $16777216, %eax
+; CHECK: # encoding: [0x3d,0x00,0x00,0x00,0x01]
+  %cmp = icmp eq i32 %tmp1, 16777216              ; <i1> [#uses=1]
+
+  %conv = zext i1 %cmp to i32                     ; <i32> [#uses=1]
+  ret i32 %conv
+
+return:                                           ; preds = %entry
+  ret i32 0
+}