[llvm-commits] [llvm] r66498 - in /llvm/branches/Apple/Dib: lib/Target/X86/X86ISelLowering.cpp test/CodeGen/X86/peep-test-0.ll test/CodeGen/X86/peep-test-1.ll test/CodeGen/X86/peep-test.ll

[Dan Gohman]

Author: djg
Date: Mon Mar  9 18:24:43 2009
New Revision: 66498

URL: http://llvm.org/viewvc/llvm-project?rev=66498&view=rev
Log:
Merge from trunk:

r66180 | djg | 2009-03-05 11:32:48 -0800 (Thu, 05 Mar 2009) | 4 lines

Fix the "test" optimization to recognize "dec" as an add of
negative one, as subtracts of immediates are canonicalized
to adds.

Added:
    llvm/branches/Apple/Dib/test/CodeGen/X86/peep-test-0.ll
    llvm/branches/Apple/Dib/test/CodeGen/X86/peep-test-1.ll
Removed:
    llvm/branches/Apple/Dib/test/CodeGen/X86/peep-test.ll
Modified:
    llvm/branches/Apple/Dib/lib/Target/X86/X86ISelLowering.cpp

Modified: llvm/branches/Apple/Dib/lib/Target/X86/X86ISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/branches/Apple/Dib/lib/Target/X86/X86ISelLowering.cpp?rev=66498&r1=66497&r2=66498&view=diff

==============================================================================
--- llvm/branches/Apple/Dib/lib/Target/X86/X86ISelLowering.cpp (original)
+++ llvm/branches/Apple/Dib/lib/Target/X86/X86ISelLowering.cpp Mon Mar  9 18:24:43 2009
@@ -5366,13 +5366,19 @@
            UE = Op.getNode()->use_end(); UI != UE; ++UI)
         if (UI->getOpcode() == ISD::STORE)
           goto default_case;
-      // An add of one will be selected as an INC.
       if (ConstantSDNode *C =
-            dyn_cast<ConstantSDNode>(Op.getNode()->getOperand(1)))
+            dyn_cast<ConstantSDNode>(Op.getNode()->getOperand(1))) {
+        // An add of one will be selected as an INC.
         if (C->getAPIntValue() == 1) {
           Opcode = X86ISD::INC;
           break;
         }
+        // An add of negative one (subtract of one) will be selected as a DEC.
+        if (C->getAPIntValue().isAllOnesValue()) {
+          Opcode = X86ISD::DEC;
+          break;
+        }
+      }
       // Otherwise use a regular EFLAGS-setting add.
       Opcode = X86ISD::ADD;
       break;
@@ -5383,13 +5389,6 @@
            UE = Op.getNode()->use_end(); UI != UE; ++UI)
         if (UI->getOpcode() == ISD::STORE)
           goto default_case;
-      // A subtract of one will be selected as a DEC.
-      if (ConstantSDNode *C =
-            dyn_cast<ConstantSDNode>(Op.getNode()->getOperand(1)))
-        if (C->getAPIntValue() == 1) {
-          Opcode = X86ISD::DEC;
-          break;
-        }
       // Otherwise use a regular EFLAGS-setting sub.
       Opcode = X86ISD::SUB;
       break;

Added: llvm/branches/Apple/Dib/test/CodeGen/X86/peep-test-0.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/branches/Apple/Dib/test/CodeGen/X86/peep-test-0.ll?rev=66498&view=auto

==============================================================================
--- llvm/branches/Apple/Dib/test/CodeGen/X86/peep-test-0.ll (added)
+++ llvm/branches/Apple/Dib/test/CodeGen/X86/peep-test-0.ll Mon Mar  9 18:24:43 2009
@@ -0,0 +1,22 @@
+; RUN: llvm-as < %s | llc -march=x86-64 > %t
+; RUN: not grep cmp %t
+; RUN: not grep test %t
+
+define void @loop(i64 %n, double* nocapture %d) nounwind {
+entry:
+	br label %bb
+
+bb:
+	%indvar = phi i64 [ %n, %entry ], [ %indvar.next, %bb ]
+	%i.03 = add i64 %indvar, %n
+	%0 = getelementptr double* %d, i64 %i.03
+	%1 = load double* %0, align 8
+	%2 = mul double %1, 3.000000e+00
+	store double %2, double* %0, align 8
+	%indvar.next = add i64 %indvar, 1
+	%exitcond = icmp eq i64 %indvar.next, 0
+	br i1 %exitcond, label %return, label %bb
+
+return:
+	ret void
+}

Added: llvm/branches/Apple/Dib/test/CodeGen/X86/peep-test-1.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/branches/Apple/Dib/test/CodeGen/X86/peep-test-1.ll?rev=66498&view=auto

==============================================================================
--- llvm/branches/Apple/Dib/test/CodeGen/X86/peep-test-1.ll (added)
+++ llvm/branches/Apple/Dib/test/CodeGen/X86/peep-test-1.ll Mon Mar  9 18:24:43 2009
@@ -0,0 +1,23 @@
+; RUN: llvm-as < %s | llc -march=x86 > %t
+; RUN: grep dec %t | count 1
+; RUN: not grep test %t
+; RUN: not grep cmp %t
+
+define void @foo(i32 %n, double* nocapture %p) nounwind {
+	br label %bb
+
+bb:
+	%indvar = phi i32 [ 0, %0 ], [ %indvar.next, %bb ]
+	%i.03 = sub i32 %n, %indvar
+	%1 = getelementptr double* %p, i32 %i.03
+	%2 = load double* %1, align 4
+	%3 = mul double %2, 2.930000e+00
+	store double %3, double* %1, align 4
+	%4 = add i32 %i.03, -1
+	%phitmp = icmp slt i32 %4, 0
+	%indvar.next = add i32 %indvar, 1
+	br i1 %phitmp, label %bb, label %return
+
+return:
+	ret void
+}

Removed: llvm/branches/Apple/Dib/test/CodeGen/X86/peep-test.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/branches/Apple/Dib/test/CodeGen/X86/peep-test.ll?rev=66497&view=auto

==============================================================================
--- llvm/branches/Apple/Dib/test/CodeGen/X86/peep-test.ll (original)
+++ llvm/branches/Apple/Dib/test/CodeGen/X86/peep-test.ll (removed)
@@ -1,22 +0,0 @@
-; RUN: llvm-as < %s | llc -march=x86-64 > %t
-; RUN: not grep cmp %t
-; RUN: not grep test %t
-
-define void @loop(i64 %n, double* nocapture %d) nounwind {
-entry:
-	br label %bb
-
-bb:
-	%indvar = phi i64 [ %n, %entry ], [ %indvar.next, %bb ]
-	%i.03 = add i64 %indvar, %n
-	%0 = getelementptr double* %d, i64 %i.03
-	%1 = load double* %0, align 8
-	%2 = mul double %1, 3.000000e+00
-	store double %2, double* %0, align 8
-	%indvar.next = add i64 %indvar, 1
-	%exitcond = icmp eq i64 %indvar.next, 0
-	br i1 %exitcond, label %return, label %bb
-
-return:
-	ret void
-}