PR target/82628

	* config/i386/predicates.md (x86_64_dwzext_immediate_operand): New.
	* config/i386/constraints.md (Wf): New constraint.
	* config/i386/i386.md (UNSPEC_SBB): New unspec.
	(cmp<dwi>_doubleword): Removed.
	(sub<mode>3_carry_ccc, *sub<mode>3_carry_ccc_1): New patterns.
	(sub<mode>3_carry_ccgz): Use unspec instead of compare.
	* config/i386/i386.c (ix86_expand_branch) <case E_TImode>: Don't
	expand with cmp<dwi>_doubleword.  For LTU and GEU use
	sub<mode>3_carry_ccc instead of sub<mode>3_carry_ccgz and use CCCmode.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@254011 138bc75d-0d04-0410-961f-82ee72b054a4

5 files changed, 109 insertions, 36 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 5a458a27cd4..cc64d7d3a2a 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,16 @@
 2017-10-23  Jakub Jelinek  <jakub@redhat.com>
 
+	PR target/82628
+	* config/i386/predicates.md (x86_64_dwzext_immediate_operand): New.
+	* config/i386/constraints.md (Wf): New constraint.
+	* config/i386/i386.md (UNSPEC_SBB): New unspec.
+	(cmp<dwi>_doubleword): Removed.
+	(sub<mode>3_carry_ccc, *sub<mode>3_carry_ccc_1): New patterns.
+	(sub<mode>3_carry_ccgz): Use unspec instead of compare.
+	* config/i386/i386.c (ix86_expand_branch) <case E_TImode>: Don't
+	expand with cmp<dwi>_doubleword.  For LTU and GEU use
+	sub<mode>3_carry_ccc instead of sub<mode>3_carry_ccgz and use CCCmode.
+
 	* common.opt (gcolumn-info): Enable by default.
 	* doc/invoke.texi (gcolumn-info): Document new default.
 
diff --git a/gcc/config/i386/constraints.md b/gcc/config/i386/constraints.md
index 98c05c9ebab..619b465f059 100644
--- a/gcc/config/i386/constraints.md
+++ b/gcc/config/i386/constraints.md
@@ -332,6 +332,11 @@
    of it satisfies the e constraint."
   (match_operand 0 "x86_64_hilo_int_operand"))
 
+(define_constraint "Wf"
+  "32-bit signed integer constant zero extended from word size
+   to double word size."
+  (match_operand 0 "x86_64_dwzext_immediate_operand"))
+
 (define_constraint "Z"
   "32-bit unsigned integer constant, or a symbolic reference known
    to fit that range (for immediate operands in zero-extending x86-64
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index ff0f6f89f91..5840a273685 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -22378,27 +22378,45 @@ ix86_expand_branch (enum rtx_code code, rtx op0, rtx op1, rtx label)
 	switch (code)
 	  {
 	  case LE: case LEU: case GT: case GTU:
-	    std::swap (op0, op1);
+	    std::swap (lo[0], lo[1]);
+	    std::swap (hi[0], hi[1]);
 	    code = swap_condition (code);
 	    /* FALLTHRU */
 
 	  case LT: case LTU: case GE: case GEU:
 	    {
-	      rtx (*cmp_insn) (rtx, rtx, rtx);
+	      rtx (*cmp_insn) (rtx, rtx);
+	      rtx (*sbb_insn) (rtx, rtx, rtx);
+	      bool uns = (code == LTU || code == GEU);
 
 	      if (TARGET_64BIT)
-		cmp_insn = gen_cmpti_doubleword;
+		{
+		  cmp_insn = gen_cmpdi_1;
+		  sbb_insn
+		    = uns ? gen_subdi3_carry_ccc : gen_subdi3_carry_ccgz;
+		}
 	      else
-		cmp_insn = gen_cmpdi_doubleword;
+		{
+		  cmp_insn = gen_cmpsi_1;
+		  sbb_insn
+		    = uns ? gen_subsi3_carry_ccc : gen_subsi3_carry_ccgz;
+		}
+
+	      if (!nonimmediate_operand (lo[0], submode))
+		lo[0] = force_reg (submode, lo[0]);
+	      if (!x86_64_general_operand (lo[1], submode))
+		lo[1] = force_reg (submode, lo[1]);
 
-	      if (!register_operand (op0, mode))
-		op0 = force_reg (mode, op0);
-	      if (!x86_64_hilo_general_operand (op1, mode))
-		op1 = force_reg (mode, op1);
+	      if (!register_operand (hi[0], submode))
+		hi[0] = force_reg (submode, hi[0]);
+	      if ((uns && !nonimmediate_operand (hi[1], submode))
+		  || (!uns && !x86_64_general_operand (hi[1], submode)))
+		hi[1] = force_reg (submode, hi[1]);
 
-	      emit_insn (cmp_insn (gen_rtx_SCRATCH (mode), op0, op1));
+	      emit_insn (cmp_insn (lo[0], lo[1]));
+	      emit_insn (sbb_insn (gen_rtx_SCRATCH (submode), hi[0], hi[1]));
 
-	      tmp = gen_rtx_REG (CCGZmode, FLAGS_REG);
+	      tmp = gen_rtx_REG (uns ? CCCmode : CCGZmode, FLAGS_REG);
 
 	      ix86_expand_branch (code, tmp, const0_rtx, label);
 	      return;
diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
index 1fc4a38b82c..57d258298aa 100644
--- a/gcc/config/i386/i386.md
+++ b/gcc/config/i386/i386.md
@@ -112,6 +112,7 @@
   UNSPEC_STOS
   UNSPEC_PEEPSIB
   UNSPEC_INSN_FALSE_DEP
+  UNSPEC_SBB
 
   ;; For SSE/MMX support:
   UNSPEC_FIX_NOTRUNC
@@ -1273,26 +1274,6 @@
 	(compare:CC (match_operand:SWI48 0 "nonimmediate_operand")
 		    (match_operand:SWI48 1 "<general_operand>")))])
 
-(define_insn_and_split "cmp<dwi>_doubleword"
-  [(set (reg:CCGZ FLAGS_REG)
-	(compare:CCGZ
-	  (match_operand:<DWI> 1 "register_operand" "0")
-	  (match_operand:<DWI> 2 "x86_64_hilo_general_operand" "ro<di>")))
-   (clobber (match_scratch:<DWI> 0 "=r"))]
-  ""
-  "#"
-  "reload_completed"
-  [(set (reg:CC FLAGS_REG)
-	(compare:CC (match_dup 1) (match_dup 2)))
-   (parallel [(set (reg:CCGZ FLAGS_REG)
-		   (compare: CCGZ
-		     (match_dup 4)
-		     (plus:DWIH
-		       (ltu:DWIH (reg:CC FLAGS_REG) (const_int 0))
-		       (match_dup 5))))
-	      (clobber (match_dup 3))])]
-  "split_double_mode (<DWI>mode, &operands[0], 3, &operands[0], &operands[3]);")
-
 (define_insn "*cmp<mode>_ccno_1"
   [(set (reg FLAGS_REG)
 	(compare (match_operand:SWI 0 "nonimmediate_operand" "<r>,?m<r>")
@@ -6911,13 +6892,46 @@
    (set_attr "pent_pair" "pu")
    (set_attr "mode" "SI")])
 
-(define_insn "*sub<mode>3_carry_ccgz"
+(define_insn "sub<mode>3_carry_ccc"
+  [(set (reg:CCC FLAGS_REG)
+	(compare:CCC
+	  (zero_extend:<DWI> (match_operand:DWIH 1 "register_operand" "0"))
+	  (plus:<DWI>
+	    (ltu:<DWI> (reg:CC FLAGS_REG) (const_int 0))
+	    (zero_extend:<DWI>
+	      (match_operand:DWIH 2 "x86_64_sext_operand" "rmWe")))))
+   (clobber (match_scratch:DWIH 0 "=r"))]
+  ""
+  "sbb{<imodesuffix>}\t{%2, %0|%0, %2}"
+  [(set_attr "type" "alu")
+   (set_attr "mode" "<MODE>")])
+
+(define_insn "*sub<mode>3_carry_ccc_1"
+  [(set (reg:CCC FLAGS_REG)
+	(compare:CCC
+	  (zero_extend:<DWI> (match_operand:DWIH 1 "register_operand" "0"))
+	  (plus:<DWI>
+	    (ltu:<DWI> (reg:CC FLAGS_REG) (const_int 0))
+	    (match_operand:<DWI> 2 "x86_64_dwzext_immediate_operand" "Wf"))))
+   (clobber (match_scratch:DWIH 0 "=r"))]
+  ""
+{
+  operands[3] = simplify_subreg (<MODE>mode, operands[2], <DWI>mode, 0);
+  return "sbb{<imodesuffix>}\t{%3, %0|%0, %3}";
+}
+  [(set_attr "type" "alu")
+   (set_attr "mode" "<MODE>")])
+
+;; The sign flag is set from the
+;; (compare (match_dup 1) (plus:DWIH (ltu:DWIH ...) (match_dup 2)))
+;; result, the overflow flag likewise, but the overflow flag is also
+;; set if the (plus:DWIH (ltu:DWIH ...) (match_dup 2)) overflows.
+(define_insn "sub<mode>3_carry_ccgz"
   [(set (reg:CCGZ FLAGS_REG)
-	(compare:CCGZ
-	  (match_operand:DWIH 1 "register_operand" "0")
-	  (plus:DWIH
-	    (ltu:DWIH (reg:CC FLAGS_REG) (const_int 0))
-	    (match_operand:DWIH 2 "x86_64_general_operand" "rme"))))
+	(unspec:CCGZ [(match_operand:DWIH 1 "register_operand" "0")
+		      (match_operand:DWIH 2 "x86_64_general_operand" "rme")
+		      (ltu:DWIH (reg:CC FLAGS_REG) (const_int 0))]
+		     UNSPEC_SBB))
    (clobber (match_scratch:DWIH 0 "=r"))]
   ""
   "sbb{<imodesuffix>}\t{%2, %0|%0, %2}"
diff --git a/gcc/config/i386/predicates.md b/gcc/config/i386/predicates.md
index 4f3f1560f45..c46dd5c83e3 100644
--- a/gcc/config/i386/predicates.md
+++ b/gcc/config/i386/predicates.md
@@ -366,6 +366,31 @@
     }
 })
 
+;; Return true if VALUE is a constant integer whose value is
+;; x86_64_immediate_operand value zero extended from word mode to mode.
+(define_predicate "x86_64_dwzext_immediate_operand"
+  (match_code "const_int,const_wide_int")
+{
+  switch (GET_CODE (op))
+    {
+    case CONST_INT:
+      if (!TARGET_64BIT)
+	return UINTVAL (op) <= HOST_WIDE_INT_UC (0xffffffff);
+      return UINTVAL (op) <= HOST_WIDE_INT_UC (0x7fffffff);
+
+    case CONST_WIDE_INT:
+      if (!TARGET_64BIT)
+	return false;
+      return (CONST_WIDE_INT_NUNITS (op) == 2
+	      && CONST_WIDE_INT_ELT (op, 1) == 0
+	      && (trunc_int_for_mode (CONST_WIDE_INT_ELT (op, 0), SImode)
+		  == (HOST_WIDE_INT) CONST_WIDE_INT_ELT (op, 0)));
+
+    default:
+      gcc_unreachable ();
+    }
+})
+
 ;; Return true if size of VALUE can be stored in a sign
 ;; extended immediate field.
 (define_predicate "x86_64_immediate_size_operand"