Author: void Date: Tue Oct 2 16:49:31 2007 New Revision: 42554 URL: http://llvm.org/viewvc/llvm-project?rev=42554&view=rev Log: Another micro-opt.
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=42554&r1=42553&r2=42554&view=diff ============================================================================== --- llvm/trunk/lib/Target/X86/README.txt (original) +++ llvm/trunk/lib/Target/X86/README.txt Tue Oct 2 16:49:31 2007 @@ -1306,3 +1306,19 @@ movl 88(%esp), %eax #481.12 //===---------------------------------------------------------------------===// + +This code: + + %tmp659 = icmp slt i16 %tmp654, 0 ; <i1> [#uses=1] + br i1 %tmp659, label %cond_true662, label %cond_next715 + +produces this: + + testw %cx, %cx + movswl %cx, %esi + jns LBB4_109 # cond_next715 + +Shark tells us that using %cx in the testw instruction is sub-optimal. It +suggests using the 32-bit register (which is what ICC uses). + +//===---------------------------------------------------------------------===// _______________________________________________ llvm-commits mailing list llvm-commits@cs.uiuc.edu http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits