Added implementation for builtin overflow detection, new patterns are listed
below.
signed addition:
add t0, t1, t2
slti t3, t2, 0
slt t4, t0, t1
bne t3, t4, overflow
unsigned addition:
add t0, t1, t2
bltu t0, t1, overflow
signed subtraction:
sub t0, t1, t2
slti t3, t2, 0
slt t4, t1, t0
bne t3, t4, overflow
signed subtraction:
add t0, t1, t2
bltu t1, t0, overflow
signed multiplication:
mulh t4, t1, t2
mul t0, t1, t2
srai t5, t0, 31/63 (RV32/64)
bne t4, t5, overflow
unsigned multiplication:
mulhu t4, t1, t2
mul t0, t1, t2
bne t4, 0, overflow
gcc/Changelog:
* config/riscv/riscv.md: Add expand pattern for <u>addv<mode>4,
<u>subv<mode>4 and <u>mulv<mode>4
* config/riscv/riscv.h: Defined riscv_min_arithmetic_precision for hook
TARGET_MIN_ARITHMETIC_PRECISION
* config/riscv/riscv.c: Set the riscv_min_arithmetic_precision to 32,
allows SImode op calls for addw/subw under RV64.
---
gcc/config/riscv/riscv.c | 8 +++
gcc/config/riscv/riscv.h | 5 ++
gcc/config/riscv/riscv.md | 104 ++++++++++++++++++++++++++++++++++++++
3 files changed, 117 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..62cebd08cff 100644
--- a/gcc/config/riscv/riscv.h
+++ b/gcc/config/riscv/riscv.h
@@ -115,6 +115,11 @@ extern const char *riscv_default_mtune (int argc, const
char **argv);
#define MAX_BITS_PER_WORD 64
+/* 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
+
/* Width of a word, in units (bytes). */
#define UNITS_PER_WORD (TARGET_64BIT ? 8 : 4)
#ifndef IN_LIBGCC2
diff --git a/gcc/config/riscv/riscv.md b/gcc/config/riscv/riscv.md
index 36012ad1f77..a95654d77e9 100644
--- a/gcc/config/riscv/riscv.md
+++ b/gcc/config/riscv/riscv.md
@@ -462,6 +462,41 @@
[(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 "" ""))]
+ ""
+{
+ 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 "" ""))]
+ ""
+{
+ 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 +553,41 @@
[(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 "" ""))]
+ ""
+{
+ 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 "" ""))]
+ ""
+{
+ 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 +679,40 @@
[(set_attr "type" "imul")
(set_attr "mode" "DI")])
+(define_expand "umulv<mode>4"
+ [(set (match_operand:X 0 "register_operand" "=r")
+ (mult:X (match_operand:X 1 "register_operand" " r")
+ (match_operand:X 2 "register_operand" " r")))
+ (label_ref (match_operand 3 "" ""))]
+ ""
+{
+ 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_expand "mulv<mode>4"
+ [(set (match_operand:X 0 "register_operand" "=r")
+ (mult:X (match_operand:X 1 "register_operand" " r")
+ (match_operand:X 2 "register_operand" " r")))
+ (label_ref (match_operand 3 "" ""))]
+ ""
+{
+ 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_insn "*mulsi3_extended"
[(set (match_operand:DI 0 "register_operand" "=r")
(sign_extend:DI
--
2.25.1
