[llvm-commits] [llvm] r128496 - in /llvm/trunk: lib/Transforms/InstCombine/InstCombineAndOrXor.cpp test/Transforms/InstCombine/sign-test-and-or.ll
Benjamin Kramer
benny.kra at googlemail.com
Tue Mar 29 15:06:41 PDT 2011
Author: d0k
Date: Tue Mar 29 17:06:41 2011
New Revision: 128496
URL: http://llvm.org/viewvc/llvm-project?rev=128496&view=rev
Log:
InstCombine: Add a few missing combines for ANDs and ORs of sign bit tests.
On x86 we now compile "if (a < 0 && b < 0)" into
testl %edi, %esi
js IF.THEN
Added:
llvm/trunk/test/Transforms/InstCombine/sign-test-and-or.ll
Modified:
llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp?rev=128496&r1=128495&r2=128496&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp Tue Mar 29 17:06:41 2011
@@ -756,6 +756,18 @@
Value *NewOr = Builder->CreateOr(Val, Val2);
return Builder->CreateICmp(LHSCC, NewOr, LHSCst);
}
+
+ // (icmp slt A, 0) & (icmp slt B, 0) --> (icmp slt (A&B), 0)
+ if (LHSCC == ICmpInst::ICMP_SLT && LHSCst->isZero()) {
+ Value *NewAnd = Builder->CreateAnd(Val, Val2);
+ return Builder->CreateICmp(LHSCC, NewAnd, LHSCst);
+ }
+
+ // (icmp sgt A, -1) & (icmp sgt B, -1) --> (icmp sgt (A|B), -1)
+ if (LHSCC == ICmpInst::ICMP_SGT && LHSCst->isAllOnesValue()) {
+ Value *NewOr = Builder->CreateOr(Val, Val2);
+ return Builder->CreateICmp(LHSCC, NewOr, LHSCst);
+ }
}
// From here on, we only handle:
@@ -1442,6 +1454,18 @@
Value *NewOr = Builder->CreateOr(Val, Val2);
return Builder->CreateICmp(LHSCC, NewOr, LHSCst);
}
+
+ // (icmp slt A, 0) | (icmp slt B, 0) --> (icmp slt (A|B), 0)
+ if (LHSCC == ICmpInst::ICMP_SLT && LHSCst->isZero()) {
+ Value *NewOr = Builder->CreateOr(Val, Val2);
+ return Builder->CreateICmp(LHSCC, NewOr, LHSCst);
+ }
+
+ // (icmp sgt A, -1) | (icmp sgt B, -1) --> (icmp sgt (A&B), -1)
+ if (LHSCC == ICmpInst::ICMP_SGT && LHSCst->isAllOnesValue()) {
+ Value *NewAnd = Builder->CreateAnd(Val, Val2);
+ return Builder->CreateICmp(LHSCC, NewAnd, LHSCst);
+ }
}
// (icmp ult (X + CA), C1) | (icmp eq X, C2) -> (icmp ule (X + CA), C1)
Added: llvm/trunk/test/Transforms/InstCombine/sign-test-and-or.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/sign-test-and-or.ll?rev=128496&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/sign-test-and-or.ll (added)
+++ llvm/trunk/test/Transforms/InstCombine/sign-test-and-or.ll Tue Mar 29 17:06:41 2011
@@ -0,0 +1,79 @@
+; RUN: opt -S -instcombine < %s | FileCheck %s
+
+declare void @foo()
+
+define void @test1(i32 %a, i32 %b) nounwind {
+ %1 = icmp slt i32 %a, 0
+ %2 = icmp slt i32 %b, 0
+ %or.cond = or i1 %1, %2
+ br i1 %or.cond, label %if.then, label %if.end
+
+; CHECK: @test1
+; CHECK-NEXT: %1 = or i32 %a, %b
+; CHECK-NEXT: %2 = icmp slt i32 %1, 0
+; CHECK-NEXT: br
+
+if.then:
+ tail call void @foo() nounwind
+ ret void
+
+if.end:
+ ret void
+}
+
+define void @test2(i32 %a, i32 %b) nounwind {
+ %1 = icmp sgt i32 %a, -1
+ %2 = icmp sgt i32 %b, -1
+ %or.cond = or i1 %1, %2
+ br i1 %or.cond, label %if.then, label %if.end
+
+; CHECK: @test2
+; CHECK-NEXT: %1 = and i32 %a, %b
+; CHECK-NEXT: %2 = icmp sgt i32 %1, -1
+; CHECK-NEXT: br
+
+if.then:
+ tail call void @foo() nounwind
+ ret void
+
+if.end:
+ ret void
+}
+
+define void @test3(i32 %a, i32 %b) nounwind {
+ %1 = icmp slt i32 %a, 0
+ %2 = icmp slt i32 %b, 0
+ %or.cond = and i1 %1, %2
+ br i1 %or.cond, label %if.then, label %if.end
+
+; CHECK: @test3
+; CHECK-NEXT: %1 = and i32 %a, %b
+; CHECK-NEXT: %2 = icmp slt i32 %1, 0
+; CHECK-NEXT: br
+
+if.then:
+ tail call void @foo() nounwind
+ ret void
+
+if.end:
+ ret void
+}
+
+define void @test4(i32 %a, i32 %b) nounwind {
+ %1 = icmp sgt i32 %a, -1
+ %2 = icmp sgt i32 %b, -1
+ %or.cond = and i1 %1, %2
+ br i1 %or.cond, label %if.then, label %if.end
+
+; CHECK: @test4
+; CHECK-NEXT: %1 = or i32 %a, %b
+; CHECK-NEXT: %2 = icmp sgt i32 %1, -1
+; CHECK-NEXT: br
+
+if.then:
+ tail call void @foo() nounwind
+ ret void
+
+if.end:
+ ret void
+}
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