[llvm] r224706 - Lower multiply-negate operation to mneg on AArch64

[Karthik Bhat]

Author: karthik
Date: Mon Dec 22 07:38:58 2014
New Revision: 224706

URL: http://llvm.org/viewvc/llvm-project?rev=224706&view=rev
Log:
Lower multiply-negate operation to mneg on AArch64

This patch pattern matches code such as-
neg	 w8, w8
mul	 w8, w9, w8
to
mneg	 w8, w8, w9

Review: http://reviews.llvm.org/D6754


Modified:
    llvm/trunk/lib/Target/AArch64/AArch64InstrInfo.td
    llvm/trunk/test/CodeGen/AArch64/dp-3source.ll

Modified: llvm/trunk/lib/Target/AArch64/AArch64InstrInfo.td
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/AArch64/AArch64InstrInfo.td?rev=224706&r1=224705&r2=224706&view=diff
==============================================================================
--- llvm/trunk/lib/Target/AArch64/AArch64InstrInfo.td (original)
+++ llvm/trunk/lib/Target/AArch64/AArch64InstrInfo.td Mon Dec 22 07:38:58 2014
@@ -657,6 +657,10 @@ def : Pat<(i32 (ineg (mul GPR32:$Rn, GPR
           (MSUBWrrr GPR32:$Rn, GPR32:$Rm, WZR)>;
 def : Pat<(i64 (ineg (mul GPR64:$Rn, GPR64:$Rm))),
           (MSUBXrrr GPR64:$Rn, GPR64:$Rm, XZR)>;
+def : Pat<(i32 (mul (ineg GPR32:$Rn), GPR32:$Rm)),
+          (MSUBWrrr GPR32:$Rn, GPR32:$Rm, WZR)>;
+def : Pat<(i64 (mul (ineg GPR64:$Rn), GPR64:$Rm)),
+          (MSUBXrrr GPR64:$Rn, GPR64:$Rm, XZR)>;
 } // AddedComplexity = 7
 
 let AddedComplexity = 5 in {

Modified: llvm/trunk/test/CodeGen/AArch64/dp-3source.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AArch64/dp-3source.ll?rev=224706&r1=224705&r2=224706&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/AArch64/dp-3source.ll (original)
+++ llvm/trunk/test/CodeGen/AArch64/dp-3source.ll Mon Dec 22 07:38:58 2014
@@ -161,3 +161,18 @@ define i64 @test_umnegl(i32 %lhs, i32 %r
 ; CHECK: umnegl {{x[0-9]+}}, {{w[0-9]+}}, {{w[0-9]+}}
   ret i64 %res
 }
+
+ at a = common global i32 0, align 4
+ at b = common global i32 0, align 4
+ at c = common global i32 0, align 4
+
+define void @test_mneg(){
+; CHECK-LABEL: test_mneg:
+  %1 = load i32* @a, align 4
+  %2 = load i32* @b, align 4
+  %3 = sub i32 0, %1
+  %4 = mul i32 %2, %3
+  store i32 %4, i32* @c, align 4
+; CHECK: mneg {{w[0-9]+}}, {{w[0-9]+}}, {{w[0-9]+}}
+  ret void
+}