[llvm-commits] [llvm] r42552 - /llvm/trunk/lib/Target/X86/README.txt

[Bill Wendling]

Author: void
Date: Tue Oct  2 16:43:06 2007
New Revision: 42552

URL: http://llvm.org/viewvc/llvm-project?rev=42552&view=rev
Log:
Another missed optimization with LICM.

Modified:
    llvm/trunk/lib/Target/X86/README.txt

Modified: llvm/trunk/lib/Target/X86/README.txt
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/README.txt?rev=42552&r1=42551&r2=42552&view=diff

==============================================================================
--- llvm/trunk/lib/Target/X86/README.txt (original)
+++ llvm/trunk/lib/Target/X86/README.txt Tue Oct  2 16:43:06 2007
@@ -1283,3 +1283,26 @@
 
 //===---------------------------------------------------------------------===//
 
+For this code:
+
+cond_next603:		; preds = %bb493, %cond_true336, %cond_next599
+	%v.21050.1 = phi i32 [ %v.21050.0, %cond_next599 ], [ %tmp344, %cond_true336 ], [ %v.2, %bb493 ]		; <i32> [#uses=1]
+	%maxz.21051.1 = phi i32 [ %maxz.21051.0, %cond_next599 ], [ 0, %cond_true336 ], [ %maxz.2, %bb493 ]		; <i32> [#uses=2]
+	%cnt.01055.1 = phi i32 [ %cnt.01055.0, %cond_next599 ], [ 0, %cond_true336 ], [ %cnt.0, %bb493 ]		; <i32> [#uses=2]
+	%byteptr.9 = phi i8* [ %byteptr.12, %cond_next599 ], [ %byteptr.0, %cond_true336 ], [ %byteptr.10, %bb493 ]		; <i8*> [#uses=9]
+	%bitptr.6 = phi i32 [ %tmp5571104.1, %cond_next599 ], [ %tmp4921049, %cond_true336 ], [ %bitptr.7, %bb493 ]		; <i32> [#uses=4]
+	%source.5 = phi i32 [ %tmp602, %cond_next599 ], [ %source.0, %cond_true336 ], [ %source.6, %bb493 ]		; <i32> [#uses=7]
+	%tmp606 = getelementptr %struct.const_tables* @tables, i32 0, i32 0, i32 %cnt.01055.1		; <i8*> [#uses=1]
+	%tmp607 = load i8* %tmp606, align 1		; <i8> [#uses=1]
+
+We produce this:
+
+LBB4_70:	# cond_next603
+	movl	-20(%ebp), %esi
+	movl	L_tables$non_lazy_ptr-"L4$pb"(%esi), %esi
+
+However, ICC caches this information before the loop and produces this:
+
+        movl      88(%esp), %eax                                #481.12
+
+//===---------------------------------------------------------------------===//