diff options
author | tstellar <tstellar@91177308-0d34-0410-b5e6-96231b3b80d8> | 2012-10-09 18:49:03 +0000 |
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committer | tstellar <tstellar@91177308-0d34-0410-b5e6-96231b3b80d8> | 2012-10-09 18:49:03 +0000 |
commit | 6b24b44a2fa24c9987b9b8d753fa8ffa841e11ac (patch) | |
tree | aca88c895c8480892471d18368aeefc0691e3be4 | |
parent | 32a8be2a172081714d9e15f7551bc381ae656126 (diff) |
R600: Fix lowering of fcmp
In most cases, R600 requires that all operands of SELECT_CC nodes have
the same type. However, we were incorrectly converting between floating
point true(1.0f) / false(0.0f) and interger true(-1) / false(0),
which was causing miscompiles for fcmp instructions that were lowered to
SELECT_CC nodes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/R600/@165526 91177308-0d34-0410-b5e6-96231b3b80d8
-rw-r--r-- | lib/Target/AMDGPU/R600ISelLowering.cpp | 19 | ||||
-rw-r--r-- | test/CodeGen/R600/fcmp-cnd.ll | 12 | ||||
-rw-r--r-- | test/CodeGen/R600/fcmp.ll | 16 | ||||
-rw-r--r-- | test/CodeGen/R600/selectcc-icmp-select-float.ll | 15 |
4 files changed, 55 insertions, 7 deletions
diff --git a/lib/Target/AMDGPU/R600ISelLowering.cpp b/lib/Target/AMDGPU/R600ISelLowering.cpp index dc3fc949d10..be92f74b25f 100644 --- a/lib/Target/AMDGPU/R600ISelLowering.cpp +++ b/lib/Target/AMDGPU/R600ISelLowering.cpp @@ -551,10 +551,8 @@ SDValue R600TargetLowering::LowerSELECT_CC(SDValue Op, SelectionDAG &DAG) const EVT CompareVT = LHS.getValueType(); // We need all the operands of SELECT_CC to have the same value type, so if - // necessary we need to convert LHS and RHS to be the same type True and - // False. True and False are guaranteed to have the same type as this - // SELECT_CC node. - + // necessary we need to change True and False to be the same type as LHS and + // RHS, and then convert the result of the select_cc back to the correct type. if (isHWTrueValue(True) && isHWFalseValue(False)) { if (CompareVT != VT) { if (VT == MVT::f32 && CompareVT == MVT::i32) { @@ -563,24 +561,31 @@ SDValue R600TargetLowering::LowerSELECT_CC(SDValue Op, SelectionDAG &DAG) const DAG.getConstant(-1, MVT::i32), DAG.getConstant(0, MVT::i32), CC); - return DAG.getNode(ISD::UINT_TO_FP, DL, VT, Boolean); + // Convert integer values of true (-1) and false (0) to fp values of + // true (1.0f) and false (0.0f). + SDValue LSB = DAG.getNode(ISD::AND, DL, MVT::i32, Boolean, + DAG.getConstant(1, MVT::i32)); + return DAG.getNode(ISD::UINT_TO_FP, DL, VT, LSB); } else if (VT == MVT::i32 && CompareVT == MVT::f32) { SDValue BoolAsFlt = DAG.getNode(ISD::SELECT_CC, DL, CompareVT, LHS, RHS, DAG.getConstantFP(1.0f, MVT::f32), DAG.getConstantFP(0.0f, MVT::f32), CC); - return DAG.getNode(ISD::FP_TO_UINT, DL, VT, BoolAsFlt); + // Convert fp values of true (1.0f) and false (0.0f) to integer values + // of true (-1) and false (0). + SDValue Neg = DAG.getNode(ISD::FNEG, DL, MVT::f32, BoolAsFlt); + return DAG.getNode(ISD::FP_TO_SINT, DL, VT, Neg); } else { // I don't think there will be any other type pairings. assert(!"Unhandled operand type parings in SELECT_CC"); } } else { + // This SELECT_CC is already legal. return DAG.getNode(ISD::SELECT_CC, DL, VT, LHS, RHS, True, False, CC); } } - // XXX If True is a hardware TRUE value and False is a hardware FALSE value, // we can handle this with a native instruction, but we need to swap true // and false and change the conditional. diff --git a/test/CodeGen/R600/fcmp-cnd.ll b/test/CodeGen/R600/fcmp-cnd.ll new file mode 100644 index 00000000000..c6b6236c100 --- /dev/null +++ b/test/CodeGen/R600/fcmp-cnd.ll @@ -0,0 +1,12 @@ +;RUN: llc < %s -march=r600 -mcpu=redwood | FileCheck %s + +;CHECK: CNDE T{{[0-9]+\.[XYZW], T[0-9]+\.[XYZW], T[0-9]+\.[XYZW], T[0-9]+\.[XYZW]}} + +define void @test(i32 addrspace(1)* %out, float addrspace(1)* %in) { +entry: + %0 = load float addrspace(1)* %in + %cmp = fcmp oeq float %0, 0.000000e+00 + %value = select i1 %cmp, i32 2, i32 3 + store i32 %value, i32 addrspace(1)* %out + ret void +} diff --git a/test/CodeGen/R600/fcmp.ll b/test/CodeGen/R600/fcmp.ll new file mode 100644 index 00000000000..4a54def50de --- /dev/null +++ b/test/CodeGen/R600/fcmp.ll @@ -0,0 +1,16 @@ +;RUN: llc < %s -march=r600 -mcpu=redwood | FileCheck %s + +;CHECK: SETE T{{[0-9]+\.[XYZW], T[0-9]+\.[XYZW], T[0-9]+\.[XYZW]}} +;CHECK: MOV T{{[0-9]+\.[XYZW], T[0-9]+\.[XYZW]}} +;CHECK: FLT_TO_INT T{{[0-9]+\.[XYZW], T[0-9]+\.[XYZW]}} + +define void @test(i32 addrspace(1)* %out, float addrspace(1)* %in) { +entry: + %0 = load float addrspace(1)* %in + %arrayidx1 = getelementptr inbounds float addrspace(1)* %in, i32 1 + %1 = load float addrspace(1)* %arrayidx1 + %cmp = fcmp oeq float %0, %1 + %sext = sext i1 %cmp to i32 + store i32 %sext, i32 addrspace(1)* %out + ret void +} diff --git a/test/CodeGen/R600/selectcc-icmp-select-float.ll b/test/CodeGen/R600/selectcc-icmp-select-float.ll new file mode 100644 index 00000000000..f1f8ab18e02 --- /dev/null +++ b/test/CodeGen/R600/selectcc-icmp-select-float.ll @@ -0,0 +1,15 @@ +; RUN: llc < %s -march=r600 -mcpu=redwood | FileCheck %s + +; Note additional optimizations may cause this SGT to be replaced with a +; CND* instruction. +; CHECK: SGT_INT T{{[0-9]+\.[XYZW], T[0-9]+\.[XYZW], T[0-9]+\.[XYZW]}} +; Test a selectcc with i32 LHS/RHS and float True/False + +define void @test(float addrspace(1)* %out, i32 addrspace(1)* %in) { +entry: + %0 = load i32 addrspace(1)* %in + %1 = icmp sge i32 %0, 0 + %2 = select i1 %1, float 1.0, float 0.0 + store float %2, float addrspace(1)* %out + ret void +} |