RISC-V: Add patterns for builtin overflow.

	gcc/
	* config/riscv/riscv.c (riscv_min_arithmetic_precision): New.
	* config/riscv/riscv.h (TARGET_MIN_ARITHMETIC_PRECISION): New.
	* config/riscv/riscv.md (addv<mode>4, uaddv<mode>4): New.
	(subv<mode>4, usubv<mode>4, mulv<mode>4, umulv<mode>4): New.

3 files changed, 257 insertions, 0 deletions

diff --git a/gcc/config/riscv/riscv.c b/gcc/config/riscv/riscv.c
index 17cdf70..e1064e3 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 d17096e..f3e8572 100644
--- a/gcc/config/riscv/riscv.h
+++ b/gcc/config/riscv/riscv.h
@@ -146,6 +146,10 @@ ASM_MISA_SPEC
 #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 c3687d5..0e35960 100644
--- a/gcc/config/riscv/riscv.md
+++ b/gcc/config/riscv/riscv.md
@@ -467,6 +467,81 @@
   [(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
@@ -523,6 +598,85 @@
   [(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
@@ -614,6 +768,97 @@
   [(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