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[RISCV] Accept c.slli/c.srli/c.srli with a 0 immediate as hints. #150689

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Merged
merged 4 commits into from
Jul 26, 2025
Merged

[RISCV] Accept c.slli/c.srli/c.srli with a 0 immediate as hints. #150689

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fb7c6b7
[RISCV] Accept c.slli/c.srli/c.srli with a 0 immediate as hints.
topperc Jul 25, 2025
3cbbff3
Merge the HINT instructions into the non-HINT instructions.
topperc Jul 26, 2025
1ce96bd
Fix test comment
topperc Jul 26, 2025
932d03f
Fix test comment
topperc Jul 26, 2025
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38 changes: 9 additions & 29 deletions llvm/lib/Target/RISCV/RISCVInstrInfoC.td
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Original file line number Diff line number Diff line change
Expand Up @@ -266,7 +266,7 @@ class Bcz<bits<3> funct3, string OpcodeStr>
let hasSideEffects = 0, mayLoad = 0, mayStore = 0 in
class Shift_right<bits<2> funct2, string OpcodeStr>
: RVInst16CB<0b100, 0b01, (outs GPRC:$rd),
(ins GPRC:$rs1, uimmlog2xlennonzero:$imm),
(ins GPRC:$rs1, uimmlog2xlen:$imm),
OpcodeStr, "$rs1, $imm"> {
let Constraints = "$rs1 = $rd";
let Inst{12} = imm{5};
Expand Down Expand Up @@ -494,7 +494,7 @@ def C_BNEZ : Bcz<0b111, "c.bnez">, Sched<[WriteJmp, ReadJmp]>;

let hasSideEffects = 0, mayLoad = 0, mayStore = 0 in
def C_SLLI : RVInst16CI<0b000, 0b10, (outs GPR:$rd_wb),
(ins GPR:$rd, uimmlog2xlennonzero:$imm),
(ins GPR:$rd, uimmlog2xlen:$imm),
"c.slli", "$rd, $imm">,
Sched<[WriteShiftImm, ReadShiftImm]> {
let Constraints = "$rd = $rd_wb";
Expand Down Expand Up @@ -612,40 +612,20 @@ def C_NOP_HINT : RVInst16CI<0b000, 0b01, (outs), (ins simm6nonzero:$imm),
let rd = 0;
}

def C_SLLI64_HINT : RVInst16CI<0b000, 0b10, (outs GPR:$rd_wb), (ins GPR:$rd),
"c.slli64", "$rd">,
Sched<[WriteShiftImm, ReadShiftImm]> {
let Constraints = "$rd = $rd_wb";
let imm = 0;
}

def C_SRLI64_HINT : RVInst16CB<0b100, 0b01, (outs GPRC:$rd),
(ins GPRC:$rs1),
"c.srli64", "$rs1">,
Sched<[WriteShiftImm, ReadShiftImm]> {
let Constraints = "$rs1 = $rd";
let Inst{6-2} = 0;
let Inst{11-10} = 0b00;
let Inst{12} = 0;
}

def C_SRAI64_HINT : RVInst16CB<0b100, 0b01, (outs GPRC:$rd),
(ins GPRC:$rs1),
"c.srai64", "$rs1">,
Sched<[WriteShiftImm, ReadShiftImm]> {
let Constraints = "$rs1 = $rd";
let Inst{6-2} = 0;
let Inst{11-10} = 0b01;
let Inst{12} = 0;
}

} // Predicates = [HasStdExtZca], hasSideEffects = 0, mayLoad = 0,
// mayStore = 0

//===----------------------------------------------------------------------===//
// Assembler Pseudo Instructions
//===----------------------------------------------------------------------===//

let Predicates = [HasStdExtZca] in {
// Legacy aliases.
def : InstAlias<"c.slli64 $rd", (C_SLLI GPR:$rd, 0), 0>;
def : InstAlias<"c.srli64 $rs1", (C_SRLI GPRC:$rs1, 0), 0>;
def : InstAlias<"c.srai64 $rs1", (C_SRAI GPRC:$rs1, 0), 0>;
}

let Predicates = [HasStdExtC, HasStdExtZihintntl] in {
def : InstAlias<"c.ntl.p1", (C_ADD X0, X2)>;
def : InstAlias<"c.ntl.pall", (C_ADD X0, X3)>;
Expand Down
64 changes: 32 additions & 32 deletions llvm/test/MC/Disassembler/RISCV/c_slli.txt
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Original file line number Diff line number Diff line change
Expand Up @@ -14,7 +14,7 @@
# RUN: -M no-aliases --show-encoding < %s 2>&1 | \
# RUN: FileCheck --check-prefix=NOHINTS %s

# GOOD: c.slli64 zero
# GOOD: c.slli zero, 0
# NOHINTS: invalid instruction encoding
0x02 0x00

Expand Down Expand Up @@ -302,7 +302,7 @@
# NOHINTS: invalid instruction encoding
0x7E 0x10

# GOOD: c.slli64 ra
# GOOD: c.slli ra, 0
0x82 0x00

# GOOD: c.slli ra, 1
Expand Down Expand Up @@ -526,7 +526,7 @@
# GOOD64: c.slli ra, 63
0xFE 0x10

# GOOD: c.slli64 sp
# GOOD: c.slli sp, 0
0x02 0x01

# GOOD: c.slli sp, 1
Expand Down Expand Up @@ -750,7 +750,7 @@
# GOOD64: c.slli sp, 63
0x7E 0x11

# GOOD: c.slli64 gp
# GOOD: c.slli gp, 0
0x82 0x01

# GOOD: c.slli gp, 1
Expand Down Expand Up @@ -974,7 +974,7 @@
# GOOD64: c.slli gp, 63
0xFE 0x11

# GOOD: c.slli64 tp
# GOOD: c.slli tp, 0
0x02 0x02

# GOOD: c.slli tp, 1
Expand Down Expand Up @@ -1198,7 +1198,7 @@
# GOOD64: c.slli tp, 63
0x7E 0x12

# GOOD: c.slli64 t0
# GOOD: c.slli t0, 0
0x82 0x02

# GOOD: c.slli t0, 1
Expand Down Expand Up @@ -1422,7 +1422,7 @@
# GOOD64: c.slli t0, 63
0xFE 0x12

# GOOD: c.slli64 t1
# GOOD: c.slli t1, 0
0x02 0x03

# GOOD: c.slli t1, 1
Expand Down Expand Up @@ -1646,7 +1646,7 @@
# GOOD64: c.slli t1, 63
0x7E 0x13

# GOOD: c.slli64 t2
# GOOD: c.slli t2, 0
0x82 0x03

# GOOD: c.slli t2, 1
Expand Down Expand Up @@ -1870,7 +1870,7 @@
# GOOD64: c.slli t2, 63
0xFE 0x13

# GOOD: c.slli64 s0
# GOOD: c.slli s0, 0
0x02 0x04

# GOOD: c.slli s0, 1
Expand Down Expand Up @@ -2094,7 +2094,7 @@
# GOOD64: c.slli s0, 63
0x7E 0x14

# GOOD: c.slli64 s1
# GOOD: c.slli s1, 0
0x82 0x04

# GOOD: c.slli s1, 1
Expand Down Expand Up @@ -2318,7 +2318,7 @@
# GOOD64: c.slli s1, 63
0xFE 0x14

# GOOD: c.slli64 a0
# GOOD: c.slli a0, 0
0x02 0x05

# GOOD: c.slli a0, 1
Expand Down Expand Up @@ -2542,7 +2542,7 @@
# GOOD64: c.slli a0, 63
0x7E 0x15

# GOOD: c.slli64 a1
# GOOD: c.slli a1, 0
0x82 0x05

# GOOD: c.slli a1, 1
Expand Down Expand Up @@ -2766,7 +2766,7 @@
# GOOD64: c.slli a1, 63
0xFE 0x15

# GOOD: c.slli64 a2
# GOOD: c.slli a2, 0
0x02 0x06

# GOOD: c.slli a2, 1
Expand Down Expand Up @@ -2990,7 +2990,7 @@
# GOOD64: c.slli a2, 63
0x7E 0x16

# GOOD: c.slli64 a3
# GOOD: c.slli a3, 0
0x82 0x06

# GOOD: c.slli a3, 1
Expand Down Expand Up @@ -3214,7 +3214,7 @@
# GOOD64: c.slli a3, 63
0xFE 0x16

# GOOD: c.slli64 a4
# GOOD: c.slli a4, 0
0x02 0x07

# GOOD: c.slli a4, 1
Expand Down Expand Up @@ -3438,7 +3438,7 @@
# GOOD64: c.slli a4, 63
0x7E 0x17

# GOOD: c.slli64 a5
# GOOD: c.slli a5, 0
0x82 0x07

# GOOD: c.slli a5, 1
Expand Down Expand Up @@ -3662,7 +3662,7 @@
# GOOD64: c.slli a5, 63
0xFE 0x17

# GOOD: c.slli64 a6
# GOOD: c.slli a6, 0
0x02 0x08

# GOOD: c.slli a6, 1
Expand Down Expand Up @@ -3886,7 +3886,7 @@
# GOOD64: c.slli a6, 63
0x7E 0x18

# GOOD: c.slli64 a7
# GOOD: c.slli a7, 0
0x82 0x08

# GOOD: c.slli a7, 1
Expand Down Expand Up @@ -4110,7 +4110,7 @@
# GOOD64: c.slli a7, 63
0xFE 0x18

# GOOD: c.slli64 s2
# GOOD: c.slli s2, 0
0x02 0x09

# GOOD: c.slli s2, 1
Expand Down Expand Up @@ -4334,7 +4334,7 @@
# GOOD64: c.slli s2, 63
0x7E 0x19

# GOOD: c.slli64 s3
# GOOD: c.slli s3, 0
0x82 0x09

# GOOD: c.slli s3, 1
Expand Down Expand Up @@ -4558,7 +4558,7 @@
# GOOD64: c.slli s3, 63
0xFE 0x19

# GOOD: c.slli64 s4
# GOOD: c.slli s4, 0
0x02 0x0A

# GOOD: c.slli s4, 1
Expand Down Expand Up @@ -4782,7 +4782,7 @@
# GOOD64: c.slli s4, 63
0x7E 0x1A

# GOOD: c.slli64 s5
# GOOD: c.slli s5, 0
0x82 0x0A

# GOOD: c.slli s5, 1
Expand Down Expand Up @@ -5006,7 +5006,7 @@
# GOOD64: c.slli s5, 63
0xFE 0x1A

# GOOD: c.slli64 s6
# GOOD: c.slli s6, 0
0x02 0x0B

# GOOD: c.slli s6, 1
Expand Down Expand Up @@ -5230,7 +5230,7 @@
# GOOD64: c.slli s6, 63
0x7E 0x1B

# GOOD: c.slli64 s7
# GOOD: c.slli s7, 0
0x82 0x0B

# GOOD: c.slli s7, 1
Expand Down Expand Up @@ -5454,7 +5454,7 @@
# GOOD64: c.slli s7, 63
0xFE 0x1B

# GOOD: c.slli64 s8
# GOOD: c.slli s8, 0
0x02 0x0C

# GOOD: c.slli s8, 1
Expand Down Expand Up @@ -5678,7 +5678,7 @@
# GOOD64: c.slli s8, 63
0x7E 0x1C

# GOOD: c.slli64 s9
# GOOD: c.slli s9, 0
0x82 0x0C

# GOOD: c.slli s9, 1
Expand Down Expand Up @@ -5902,7 +5902,7 @@
# GOOD64: c.slli s9, 63
0xFE 0x1C

# GOOD: c.slli64 s10
# GOOD: c.slli s10, 0
0x02 0x0D

# GOOD: c.slli s10, 1
Expand Down Expand Up @@ -6126,7 +6126,7 @@
# GOOD64: c.slli s10, 63
0x7E 0x1D

# GOOD: c.slli64 s11
# GOOD: c.slli s11, 0
0x82 0x0D

# GOOD: c.slli s11, 1
Expand Down Expand Up @@ -6350,7 +6350,7 @@
# GOOD64: c.slli s11, 63
0xFE 0x1D

# GOOD: c.slli64 t3
# GOOD: c.slli t3, 0
0x02 0x0E

# GOOD: c.slli t3, 1
Expand Down Expand Up @@ -6574,7 +6574,7 @@
# GOOD64: c.slli t3, 63
0x7E 0x1E

# GOOD: c.slli64 t4
# GOOD: c.slli t4, 0
0x82 0x0E

# GOOD: c.slli t4, 1
Expand Down Expand Up @@ -6798,7 +6798,7 @@
# GOOD64: c.slli t4, 63
0xFE 0x1E

# GOOD: c.slli64 t5
# GOOD: c.slli t5, 0
0x02 0x0F

# GOOD: c.slli t5, 1
Expand Down Expand Up @@ -7022,7 +7022,7 @@
# GOOD64: c.slli t5, 63
0x7E 0x1F

# GOOD: c.slli64 t6
# GOOD: c.slli t6, 0
0x82 0x0F

# GOOD: c.slli t6, 1
Expand Down
7 changes: 3 additions & 4 deletions llvm/test/MC/RISCV/rv32c-invalid.s
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Original file line number Diff line number Diff line change
Expand Up @@ -35,10 +35,9 @@ c.addi16sp t0, 16 # CHECK: :[[@LINE]]:13: error: register must be sp (x2)

# Out of range immediates

## uimmlog2xlennonzero
c.slli t0, 64 # CHECK: :[[@LINE]]:12: error: immediate must be an integer in the range [1, 31]
c.srli a0, 32 # CHECK: :[[@LINE]]:12: error: immediate must be an integer in the range [1, 31]
c.srai a0, 0 # CHECK: :[[@LINE]]:12: error: immediate must be an integer in the range [1, 31]
## uimmlog2xlenn
c.slli t0, 64 # CHECK: :[[@LINE]]:12: error: immediate must be an integer in the range [0, 31]
c.srli a0, 32 # CHECK: :[[@LINE]]:12: error: immediate must be an integer in the range [0, 31]

## simm6
c.li t0, 128 # CHECK: :[[@LINE]]:10: error: immediate must be an integer in the range [-32, 31]
Expand Down
7 changes: 3 additions & 4 deletions llvm/test/MC/RISCV/rv64c-invalid.s
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Expand Up @@ -13,10 +13,9 @@ c.ldsp zero, 4(sp) # CHECK: :[[@LINE]]:9: error: register must be a GPR excludi

# Out of range immediates

## uimmlog2xlennonzero
c.slli t0, 64 # CHECK: :[[@LINE]]:12: error: immediate must be an integer in the range [1, 63]
c.srli a0, -1 # CHECK: :[[@LINE]]:12: error: immediate must be an integer in the range [1, 63]
c.srai a0, 0 # CHECK: :[[@LINE]]:12: error: immediate must be an integer in the range [1, 63]
## uimmlog2xlen
c.slli t0, 64 # CHECK: :[[@LINE]]:12: error: immediate must be an integer in the range [0, 63]
c.srli a0, -1 # CHECK: :[[@LINE]]:12: error: immediate must be an integer in the range [0, 63]

## simm6
c.addiw t0, -33 # CHECK: :[[@LINE]]:13: error: immediate must be an integer in the range [-32, 31]
Expand Down
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