RPCS3/llvm-mirror
1
0
Fork 0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-11-23 03:02:36 +01:00
Code Issues Projects Releases Wiki Activity

Fix PR5694. The CMN instructions set the flags differently from CMP, so they

Browse Source 
cannot be directly interchanged for comparisons against negated values.
Disable the CMN instructions for the time being.

llvm-svn: 94119
This commit is contained in:
Jim Grosbach 2010-01-22 00:08:13 +00:00
parent 30dee16eed
commit 231a0d01a9
5 changed files with 31 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
lib/Target/ARM/ARMInstrInfo.td
View File

@ -1539,8 +1539,10 @@ def : ARMV6Pat<(or (and GPR:$src1, 0xFFFF0000),
defm CMP : AI1_cmp_irs<0b1010, "cmp",
BinOpFrag<(ARMcmp node:$LHS, node:$RHS)>>;
defm CMN : AI1_cmp_irs<0b1011, "cmn",
BinOpFrag<(ARMcmp node:$LHS,(ineg node:$RHS))>>;
//FIXME: Disable CMN, as CCodes are backwards from compare expectations
// Compare-to-zero still works out, just not the relationals
//defm CMN : AI1_cmp_irs<0b1011, "cmn",
// BinOpFrag<(ARMcmp node:$LHS,(ineg node:$RHS))>>;
// Note that TST/TEQ don't set all the same flags that CMP does!
defm TST : AI1_cmp_irs<0b1000, "tst",
@ -1553,11 +1555,11 @@ defm CMPz : AI1_cmp_irs<0b1010, "cmp",
defm CMNz : AI1_cmp_irs<0b1011, "cmn",
BinOpFrag<(ARMcmpZ node:$LHS,(ineg node:$RHS))>>;
def : ARMPat<(ARMcmp GPR:$src, so_imm_neg:$imm),
(CMNri GPR:$src, so_imm_neg:$imm)>;
//def : ARMPat<(ARMcmp GPR:$src, so_imm_neg:$imm),
// (CMNri GPR:$src, so_imm_neg:$imm)>;
def : ARMPat<(ARMcmpZ GPR:$src, so_imm_neg:$imm),
(CMNri GPR:$src, so_imm_neg:$imm)>;
(CMNzri GPR:$src, so_imm_neg:$imm)>;
// Conditional moves

10
lib/Target/ARM/ARMInstrThumb.td
View File

@ -534,10 +534,12 @@ def tBIC : T1sIt<(outs tGPR:$dst), (ins tGPR:$lhs, tGPR:$rhs), IIC_iALUr,
// CMN register
let Defs = [CPSR] in {
def tCMN : T1pI<(outs), (ins tGPR:$lhs, tGPR:$rhs), IIC_iCMPr,
"cmn", "\t$lhs, $rhs",
[(ARMcmp tGPR:$lhs, (ineg tGPR:$rhs))]>,
T1DataProcessing<0b1011>;
//FIXME: Disable CMN, as CCodes are backwards from compare expectations
// Compare-to-zero still works out, just not the relationals
//def tCMN : T1pI<(outs), (ins tGPR:$lhs, tGPR:$rhs), IIC_iCMPr,
// "cmn", "\t$lhs, $rhs",
// [(ARMcmp tGPR:$lhs, (ineg tGPR:$rhs))]>,
// T1DataProcessing<0b1011>;
def tCMNz : T1pI<(outs), (ins tGPR:$lhs, tGPR:$rhs), IIC_iCMPr,
"cmn", "\t$lhs, $rhs",
[(ARMcmpZ tGPR:$lhs, (ineg tGPR:$rhs))]>,

12
lib/Target/ARM/ARMInstrThumb2.td
View File

@ -1609,16 +1609,18 @@ defm t2CMP : T2I_cmp_irs<0b1101, "cmp",
defm t2CMPz : T2I_cmp_irs<0b1101, "cmp",
BinOpFrag<(ARMcmpZ node:$LHS, node:$RHS)>>;
defm t2CMN : T2I_cmp_irs<0b1000, "cmn",
BinOpFrag<(ARMcmp node:$LHS,(ineg node:$RHS))>>;
//FIXME: Disable CMN, as CCodes are backwards from compare expectations
// Compare-to-zero still works out, just not the relationals
//defm t2CMN : T2I_cmp_irs<0b1000, "cmn",
// BinOpFrag<(ARMcmp node:$LHS,(ineg node:$RHS))>>;
defm t2CMNz : T2I_cmp_irs<0b1000, "cmn",
BinOpFrag<(ARMcmpZ node:$LHS,(ineg node:$RHS))>>;
def : T2Pat<(ARMcmp GPR:$src, t2_so_imm_neg:$imm),
(t2CMNri GPR:$src, t2_so_imm_neg:$imm)>;
//def : T2Pat<(ARMcmp GPR:$src, t2_so_imm_neg:$imm),
// (t2CMNri GPR:$src, t2_so_imm_neg:$imm)>;
def : T2Pat<(ARMcmpZ GPR:$src, t2_so_imm_neg:$imm),
(t2CMNri GPR:$src, t2_so_imm_neg:$imm)>;
(t2CMNzri GPR:$src, t2_so_imm_neg:$imm)>;
defm t2TST : T2I_cmp_irs<0b0000, "tst",
BinOpFrag<(ARMcmpZ (and node:$LHS, node:$RHS), 0)>>;

9
lib/Target/ARM/README.txt
View File

@ -596,3 +596,12 @@ Make use of the "rbit" instruction.
Take a look at test/CodeGen/Thumb2/machine-licm.ll. ARM should be taught how
to licm and cse the unnecessary load from cp#1.
//===---------------------------------------------------------------------===//
The CMN instruction sets the flags like an ADD instruction, while CMP sets
them like a subtract. Therefore to be able to use CMN for comparisons other
than the Z bit, we'll need additional logic to reverse the conditionals
associated with the comparison. Perhaps a pseudo-instruction for the comparison,
with a post-codegen pass to clean up and handle the condition codes?
See PR5694 for testcase.

3
lib/Target/ARM/Thumb2SizeReduction.cpp
View File

@ -65,7 +65,8 @@ namespace {
{ ARM::t2ASRri, ARM::tASRri, 0, 5, 0, 1, 0, 0,0, 0 },
{ ARM::t2ASRrr, 0, ARM::tASRrr, 0, 0, 0, 1, 0,0, 0 },
{ ARM::t2BICrr, 0, ARM::tBIC, 0, 0, 0, 1, 0,0, 0 },
{ ARM::t2CMNrr, ARM::tCMN, 0, 0, 0, 1, 0, 2,0, 0 },
//FIXME: Disable CMN, as CCodes are backwards from compare expectations
//{ ARM::t2CMNrr, ARM::tCMN, 0, 0, 0, 1, 0, 2,0, 0 },
{ ARM::t2CMPri, ARM::tCMPi8, 0, 8, 0, 1, 0, 2,0, 0 },
{ ARM::t2CMPrr, ARM::tCMPhir, 0, 0, 0, 0, 0, 2,0, 0 },
{ ARM::t2CMPzri,ARM::tCMPzi8, 0, 8, 0, 1, 0, 2,0, 0 },