[llvm] r218251 - R600/SI: Use ISD::MUL instead of ISD::UMULO when lowering division

Tom Stellard thomas.stellard at amd.com
Mon Sep 22 08:35:31 PDT 2014


Author: tstellar
Date: Mon Sep 22 10:35:30 2014
New Revision: 218251

URL: http://llvm.org/viewvc/llvm-project?rev=218251&view=rev
Log:
R600/SI: Use ISD::MUL instead of ISD::UMULO when lowering division

ISD::MUL and ISD:UMULO are the same except that UMULO sets an overflow
bit.  Since we aren't using the overflow bit, we should use ISD::MUL.

Modified:
    llvm/trunk/lib/Target/R600/AMDGPUISelLowering.cpp

Modified: llvm/trunk/lib/Target/R600/AMDGPUISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/R600/AMDGPUISelLowering.cpp?rev=218251&r1=218250&r2=218251&view=diff
==============================================================================
--- llvm/trunk/lib/Target/R600/AMDGPUISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/R600/AMDGPUISelLowering.cpp Mon Sep 22 10:35:30 2014
@@ -1515,8 +1515,8 @@ SDValue AMDGPUTargetLowering::LowerUDIVR
   // e is rounding error.
   SDValue RCP = DAG.getNode(AMDGPUISD::URECIP, DL, VT, Den);
 
-  // RCP_LO = umulo(RCP, Den) */
-  SDValue RCP_LO = DAG.getNode(ISD::UMULO, DL, VT, RCP, Den);
+  // RCP_LO = mul(RCP, Den) */
+  SDValue RCP_LO = DAG.getNode(ISD::MUL, DL, VT, RCP, Den);
 
   // RCP_HI = mulhu (RCP, Den) */
   SDValue RCP_HI = DAG.getNode(ISD::MULHU, DL, VT, RCP, Den);
@@ -1547,7 +1547,7 @@ SDValue AMDGPUTargetLowering::LowerUDIVR
   SDValue Quotient = DAG.getNode(ISD::MULHU, DL, VT, Tmp0, Num);
 
   // Num_S_Remainder = Quotient * Den
-  SDValue Num_S_Remainder = DAG.getNode(ISD::UMULO, DL, VT, Quotient, Den);
+  SDValue Num_S_Remainder = DAG.getNode(ISD::MUL, DL, VT, Quotient, Den);
 
   // Remainder = Num - Num_S_Remainder
   SDValue Remainder = DAG.getNode(ISD::SUB, DL, VT, Num, Num_S_Remainder);





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