[PATCH] [RISCV] Add Pattern for builtin overflow
Levy Hsu
admin@levyhsu.com
Thu Apr 29 05:42:04 GMT 2021
From: LevyHsu <admin@levyhsu.com>
Added implementation for builtin overflow detection, new patterns are listed below.
---------------------------------------------------------------
Addition:
signed addition (SImode in RV32 || DImode in RV64):
add t0, t1, t2
slti t3, t2, 0
slt t4, t0, t1
bne t3, t4, overflow
signed addition (SImode in RV64):
add t0, t1, t2
addw t3, t1, t2
bne t0, t3, overflow
unsigned addition (SImode in RV32 || DImode in RV64):
add t0, t1, t2
bltu t0, t1, overflow
unsigned addition (SImode in RV64):
sext.w t3, t1
addw t0, t1, t2
bltu t0, t3, overflow
---------------------------------------------------------------
Subtraction:
signed subtraction (SImode in RV32 || DImode in RV64):
sub t0, t1, t2
slti t3, t2, 0
slt t4, t1, t0
bne t3, t4, overflow
signed subtraction (SImode in RV64):
sub t0, t1, t2
subw t3, t1, t2
bne t0, t3, overflow
unsigned subtraction (SImode in RV32 || DImode in RV64):
add t0, t1, t2
bltu t1, t0, overflow
unsigned subtraction (SImode in RV64):
sext.w t3, t1
subw t0, t1, t2
bltu t0, t3, overflow
---------------------------------------------------------------
Multiplication:
signed multiplication (SImode in RV32 || DImode in RV64):
mulh t3, t1, t2
mul t0, t1, t2
srai t4, t0, 31/63 (RV32/64)
bne t3, t4, overflow
signed multiplication (SImode in RV64):
mul t0, t1, t2
sext.w t3, t0
bne t0, t3, overflow
unsigned multiplication (SImode in RV32 || DImode in RV64 ):
mulhu t3, t1, t2
mul t0, t1, t2
bne t3, 0, overflow
unsigned multiplication (SImode in RV64):
slli t0, t0, 32
slli t1, t1, 32
mulhu t2, t1, t1
srli t3, t2, 32
bne t3, 0, overflow
sext.w t2, t2
Speical Thanks to:
Jim Wilson, for the throughout help and advice on gcc and gdb.
Craig Topper, for pointing out the SImode operand needs sext.w for unsigned add/sub in RV64.
Andrew Waterman. For better SImode signed add/sub and unsigned mul pattern in RV64.
Kito Cheng, for patch submission.
---
gcc/config/riscv/riscv.c | 8 ++
gcc/config/riscv/riscv.h | 4 +
gcc/config/riscv/riscv.md | 243 ++++++++++++++++++++++++++++++++++++++
3 files changed, 255 insertions(+)
diff --git a/gcc/config/riscv/riscv.c b/gcc/config/riscv/riscv.c
index d489717b2a5..cf94f5c9658 100644
--- a/gcc/config/riscv/riscv.c
+++ b/gcc/config/riscv/riscv.c
@@ -351,6 +351,14 @@ static const struct riscv_tune_info riscv_tune_info_table[] = {
{ "size", generic, &optimize_size_tune_info },
};
+/* Implement TARGET_MIN_ARITHMETIC_PRECISION. */
+
+static unsigned int
+riscv_min_arithmetic_precision (void)
+{
+ return 32;
+}
+
/* Return the riscv_tune_info entry for the given name string. */
static const struct riscv_tune_info *
diff --git a/gcc/config/riscv/riscv.h b/gcc/config/riscv/riscv.h
index 172c7ca7c98..0521c8881ae 100644
--- a/gcc/config/riscv/riscv.h
+++ b/gcc/config/riscv/riscv.h
@@ -121,6 +121,10 @@ extern const char *riscv_default_mtune (int argc, const char **argv);
#define MIN_UNITS_PER_WORD 4
#endif
+/* Allows SImode op in builtin overflow pattern, see internal-fn.c. */
+#undef TARGET_MIN_ARITHMETIC_PRECISION
+#define TARGET_MIN_ARITHMETIC_PRECISION riscv_min_arithmetic_precision
+
/* The `Q' extension is not yet supported. */
#define UNITS_PER_FP_REG (TARGET_DOUBLE_FLOAT ? 8 : 4)
diff --git a/gcc/config/riscv/riscv.md b/gcc/config/riscv/riscv.md
index 36012ad1f77..a6e14fdc24d 100644
--- a/gcc/config/riscv/riscv.md
+++ b/gcc/config/riscv/riscv.md
@@ -462,6 +462,80 @@
[(set_attr "type" "arith")
(set_attr "mode" "DI")])
+(define_expand "addv<mode>4"
+ [(set (match_operand:GPR 0 "register_operand" "=r,r")
+ (plus:GPR (match_operand:GPR 1 "register_operand" " r,r")
+ (match_operand:GPR 2 "arith_operand" " r,I")))
+ (label_ref (match_operand 3 "" ""))]
+ ""
+{
+ if (TARGET_64BIT && <MODE>mode == SImode)
+ {
+ rtx t3 = gen_reg_rtx (DImode);
+ rtx t4 = gen_reg_rtx (DImode);
+ rtx t5 = gen_reg_rtx (DImode);
+ rtx t6 = gen_reg_rtx (DImode);
+
+ emit_insn (gen_addsi3 (operands[0], operands[1], operands[2]));
+ if (GET_CODE (operands[1]) != CONST_INT)
+ emit_insn (gen_extend_insn (t4, operands[1], DImode, SImode, 0));
+ else
+ t4 = operands[1];
+ if (GET_CODE (operands[2]) != CONST_INT)
+ emit_insn (gen_extend_insn (t5, operands[2], DImode, SImode, 0));
+ else
+ t5 = operands[2];
+ emit_insn (gen_adddi3 (t3, t4, t5));
+ emit_insn (gen_extend_insn (t6, operands[0], DImode, SImode, 0));
+
+ riscv_expand_conditional_branch (operands[3], NE, t6, t3);
+ }
+ else
+ {
+ rtx t3 = gen_reg_rtx (<MODE>mode);
+ rtx t4 = gen_reg_rtx (<MODE>mode);
+
+ emit_insn (gen_add3_insn (operands[0], operands[1], operands[2]));
+ rtx cmp1 = gen_rtx_LT (<MODE>mode, operands[2], const0_rtx);
+ emit_insn (gen_cstore<mode>4 (t3, cmp1, operands[2], const0_rtx));
+ rtx cmp2 = gen_rtx_LT (<MODE>mode, operands[0], operands[1]);
+
+ emit_insn (gen_cstore<mode>4 (t4, cmp2, operands[0], operands[1]));
+ riscv_expand_conditional_branch (operands[3], NE, t3, t4);
+ }
+ DONE;
+})
+
+(define_expand "uaddv<mode>4"
+ [(set (match_operand:GPR 0 "register_operand" "=r,r")
+ (plus:GPR (match_operand:GPR 1 "register_operand" " r,r")
+ (match_operand:GPR 2 "arith_operand" " r,I")))
+ (label_ref (match_operand 3 "" ""))]
+ ""
+{
+ if (TARGET_64BIT && <MODE>mode == SImode)
+ {
+ rtx t3 = gen_reg_rtx (DImode);
+ rtx t4 = gen_reg_rtx (DImode);
+
+ if (GET_CODE (operands[1]) != CONST_INT)
+ emit_insn (gen_extend_insn (t3, operands[1], DImode, SImode, 0));
+ else
+ t3 = operands[1];
+ emit_insn (gen_addsi3 (operands[0], operands[1], operands[2]));
+ emit_insn (gen_extend_insn (t4, operands[0], DImode, SImode, 0));
+
+ riscv_expand_conditional_branch (operands[3], LTU, t4, t3);
+ }
+ else
+ {
+ emit_insn (gen_add3_insn (operands[0], operands[1], operands[2]));
+ riscv_expand_conditional_branch (operands[3], LTU, operands[0], operands[1]);
+ }
+
+ DONE;
+})
+
(define_insn "*addsi3_extended"
[(set (match_operand:DI 0 "register_operand" "=r,r")
(sign_extend:DI
@@ -518,6 +592,85 @@
[(set_attr "type" "arith")
(set_attr "mode" "SI")])
+(define_expand "subv<mode>4"
+ [(set (match_operand:GPR 0 "register_operand" "= r")
+ (minus:GPR (match_operand:GPR 1 "reg_or_0_operand" " rJ")
+ (match_operand:GPR 2 "register_operand" " r")))
+ (label_ref (match_operand 3 "" ""))]
+ ""
+{
+
+ if (TARGET_64BIT && <MODE>mode == SImode)
+ {
+ rtx t3 = gen_reg_rtx (DImode);
+ rtx t4 = gen_reg_rtx (DImode);
+ rtx t5 = gen_reg_rtx (DImode);
+ rtx t6 = gen_reg_rtx (DImode);
+
+ emit_insn (gen_subsi3 (operands[0], operands[1], operands[2]));
+ if (GET_CODE (operands[1]) != CONST_INT)
+ emit_insn (gen_extend_insn (t4, operands[1], DImode, SImode, 0));
+ else
+ t4 = operands[1];
+ if (GET_CODE (operands[2]) != CONST_INT)
+ emit_insn (gen_extend_insn (t5, operands[2], DImode, SImode, 0));
+ else
+ t5 = operands[2];
+ emit_insn (gen_subdi3 (t3, t4, t5));
+ emit_insn (gen_extend_insn (t6, operands[0], DImode, SImode, 0));
+
+ riscv_expand_conditional_branch (operands[3], NE, t6, t3);
+ }
+ else
+ {
+ rtx t3 = gen_reg_rtx (<MODE>mode);
+ rtx t4 = gen_reg_rtx (<MODE>mode);
+
+ emit_insn (gen_sub3_insn (operands[0], operands[1], operands[2]));
+
+ rtx cmp1 = gen_rtx_LT (<MODE>mode, operands[2], const0_rtx);
+ emit_insn (gen_cstore<mode>4 (t3, cmp1, operands[2], const0_rtx));
+
+ rtx cmp2 = gen_rtx_LT (<MODE>mode, operands[1], operands[0]);
+ emit_insn (gen_cstore<mode>4 (t4, cmp2, operands[1], operands[0]));
+
+ riscv_expand_conditional_branch (operands[3], NE, t3, t4);
+ }
+
+ DONE;
+})
+
+(define_expand "usubv<mode>4"
+ [(set (match_operand:GPR 0 "register_operand" "= r")
+ (minus:GPR (match_operand:GPR 1 "reg_or_0_operand" " rJ")
+ (match_operand:GPR 2 "register_operand" " r")))
+ (label_ref (match_operand 3 "" ""))]
+ ""
+{
+ if (TARGET_64BIT && <MODE>mode == SImode)
+ {
+ rtx t3 = gen_reg_rtx (DImode);
+ rtx t4 = gen_reg_rtx (DImode);
+
+ if (GET_CODE (operands[1]) != CONST_INT)
+ emit_insn (gen_extend_insn (t3, operands[1], DImode, SImode, 0));
+ else
+ t3 = operands[1];
+ emit_insn (gen_subsi3 (operands[0], operands[1], operands[2]));
+ emit_insn (gen_extend_insn (t4, operands[0], DImode, SImode, 0));
+
+ riscv_expand_conditional_branch (operands[3], LTU, t3, t4);
+ }
+ else
+ {
+ emit_insn (gen_sub3_insn (operands[0], operands[1], operands[2]));
+ riscv_expand_conditional_branch (operands[3], LTU, operands[1], operands[0]);
+ }
+
+ DONE;
+})
+
+
(define_insn "*subsi3_extended"
[(set (match_operand:DI 0 "register_operand" "= r")
(sign_extend:DI
@@ -609,6 +762,96 @@
[(set_attr "type" "imul")
(set_attr "mode" "DI")])
+(define_expand "mulv<mode>4"
+ [(set (match_operand:GPR 0 "register_operand" "=r")
+ (mult:GPR (match_operand:GPR 1 "register_operand" " r")
+ (match_operand:GPR 2 "register_operand" " r")))
+ (label_ref (match_operand 3 "" ""))]
+ "TARGET_MUL"
+{
+ if (TARGET_64BIT && <MODE>mode == SImode)
+ {
+ rtx t3 = gen_reg_rtx (DImode);
+ rtx t4 = gen_reg_rtx (DImode);
+ rtx t5 = gen_reg_rtx (DImode);
+ rtx t6 = gen_reg_rtx (DImode);
+
+ if (GET_CODE (operands[1]) != CONST_INT)
+ emit_insn (gen_extend_insn (t4, operands[1], DImode, SImode, 0));
+ else
+ t4 = operands[1];
+ if (GET_CODE (operands[2]) != CONST_INT)
+ emit_insn (gen_extend_insn (t5, operands[2], DImode, SImode, 0));
+ else
+ t5 = operands[2];
+ emit_insn (gen_muldi3 (t3, t4, t5));
+
+ emit_move_insn (operands[0], gen_lowpart (SImode, t3));
+ emit_insn (gen_extend_insn (t6, operands[0], DImode, SImode, 0));
+
+ riscv_expand_conditional_branch (operands[3], NE, t6, t3);
+ }
+ else
+ {
+ rtx hp = gen_reg_rtx (<MODE>mode);
+ rtx lp = gen_reg_rtx (<MODE>mode);
+
+ emit_insn (gen_mul<mode>3_highpart (hp, operands[1], operands[2]));
+ emit_insn (gen_mul<mode>3 (operands[0], operands[1], operands[2]));
+ emit_insn (gen_ashr<mode>3 (lp, operands[0], GEN_INT (BITS_PER_WORD - 1)));
+
+ riscv_expand_conditional_branch (operands[3], NE, hp, lp);
+ }
+
+ DONE;
+})
+
+(define_expand "umulv<mode>4"
+ [(set (match_operand:GPR 0 "register_operand" "=r")
+ (mult:GPR (match_operand:GPR 1 "register_operand" " r")
+ (match_operand:GPR 2 "register_operand" " r")))
+ (label_ref (match_operand 3 "" ""))]
+ "TARGET_MUL"
+{
+if (TARGET_64BIT && <MODE>mode == SImode)
+ {
+ rtx t3 = gen_reg_rtx (DImode);
+ rtx t4 = gen_reg_rtx (DImode);
+ rtx t5 = gen_reg_rtx (DImode);
+ rtx t6 = gen_reg_rtx (DImode);
+ rtx t7 = gen_reg_rtx (DImode);
+ rtx t8 = gen_reg_rtx (DImode);
+
+ if (GET_CODE (operands[1]) != CONST_INT)
+ emit_insn (gen_extend_insn (t3, operands[1], DImode, SImode, 0));
+ else
+ t3 = operands[1];
+ if (GET_CODE (operands[2]) != CONST_INT)
+ emit_insn (gen_extend_insn (t4, operands[2], DImode, SImode, 0));
+ else
+ t4 = operands[2];
+
+ emit_insn (gen_ashldi3 (t5, t3, GEN_INT (32)));
+ emit_insn (gen_ashldi3 (t6, t4, GEN_INT (32)));
+ emit_insn (gen_umuldi3_highpart (t7, t5, t6));
+ emit_move_insn (operands[0], gen_lowpart (SImode, t7));
+ emit_insn (gen_lshrdi3 (t8, t7, GEN_INT (32)));
+
+ riscv_expand_conditional_branch (operands[3], NE, t8, const0_rtx);
+ }
+ else
+ {
+ rtx hp = gen_reg_rtx (<MODE>mode);
+
+ emit_insn (gen_umul<mode>3_highpart (hp, operands[1], operands[2]));
+ emit_insn (gen_mul<mode>3 (operands[0], operands[1], operands[2]));
+
+ riscv_expand_conditional_branch (operands[3], NE, hp, const0_rtx);
+ }
+
+ DONE;
+})
+
(define_insn "*mulsi3_extended"
[(set (match_operand:DI 0 "register_operand" "=r")
(sign_extend:DI
--
2.31.1
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