Use vec_extact_lo instead of subreg in reduc_<code>_scal_m.

Loop vectorizer will use vec_perm to select lower part of a vector,
there could be some redundancy when using subreg in
reduc_<code>_scal_m, because rtl cse can't figure out vec_select lower
part is just subreg.

I'm trying to canonicalize vec_select to subreg like aarch64 did, but
there're so many regressions, some are easy to fix, some requires
middle-end adjustment.

So for simplicity, the patch use vec_select instead of subreg in
reduc_<code>_scal_m.

gcc/ChangeLog:

	* config/i386/sse.md: (reduc_plus_scal_<mode>): Use
	vec_extract_lo instead of subreg.
	(reduc_<code>_scal_<mode>): Ditto.
	(reduc_<code>_scal_<mode>): Ditto.
	(reduc_<code>_scal_<mode>): Ditto.
	(reduc_<code>_scal_<mode>): Ditto.

diff --git a/gcc/config/i386/sse.md b/gcc/config/i386/sse.md
index 4f511693e3ff5d4ff449998c70f6eb4186f931be..5e0e0e9e51f9ef687efc670fc6ee586984744de4 100644 (file)
--- a/gcc/config/i386/sse.md
+++ b/gcc/config/i386/sse.md
@@ -3480,11 +3480,12 @@
  ""
 {
   rtx tmp = gen_reg_rtx (<ssehalfvecmode>mode);
-  emit_insn (gen_vec_extract_hi_<mode> (tmp, operands[1]));
   rtx tmp2 = gen_reg_rtx (<ssehalfvecmode>mode);
-  rtx tmp3 = gen_lowpart (<ssehalfvecmode>mode, operands[1]);
-  emit_insn (gen_add<ssehalfvecmodelower>3 (tmp2, tmp, tmp3));
-  emit_insn (gen_reduc_plus_scal_<ssehalfvecmodelower> (operands[0], tmp2));
+  rtx tmp3 = gen_reg_rtx (<ssehalfvecmode>mode);
+  emit_insn (gen_vec_extract_hi_<mode> (tmp, operands[1]));
+  emit_insn (gen_vec_extract_lo_<mode> (tmp2, operands[1]));
+  emit_insn (gen_add<ssehalfvecmodelower>3 (tmp3, tmp, tmp2));
+  emit_insn (gen_reduc_plus_scal_<ssehalfvecmodelower> (operands[0], tmp3));
   DONE;
 })
 
@@ -3528,11 +3529,12 @@
   ""
 {
   rtx tmp = gen_reg_rtx (<ssehalfvecmode>mode);
-  emit_insn (gen_vec_extract_hi_<mode> (tmp, operands[1]));
   rtx tmp2 = gen_reg_rtx (<ssehalfvecmode>mode);
-  emit_insn (gen_<code><ssehalfvecmodelower>3
-    (tmp2, tmp, gen_lowpart (<ssehalfvecmode>mode, operands[1])));
-  emit_insn (gen_reduc_<code>_scal_<ssehalfvecmodelower> (operands[0], tmp2));
+  rtx tmp3 = gen_reg_rtx (<ssehalfvecmode>mode);
+  emit_insn (gen_vec_extract_hi_<mode> (tmp, operands[1]));
+  emit_insn (gen_vec_extract_lo_<mode> (tmp2, operands[1]));
+  emit_insn (gen_<code><ssehalfvecmodelower>3 (tmp3, tmp, tmp2));
+  emit_insn (gen_reduc_<code>_scal_<ssehalfvecmodelower> (operands[0], tmp3));
   DONE;
 })
 
@@ -3543,11 +3545,12 @@
   "TARGET_AVX512F"
 {
   rtx tmp = gen_reg_rtx (<ssehalfvecmode>mode);
-  emit_insn (gen_vec_extract_hi_<mode> (tmp, operands[1]));
   rtx tmp2 = gen_reg_rtx (<ssehalfvecmode>mode);
-  emit_insn (gen_<code><ssehalfvecmodelower>3
-    (tmp2, tmp, gen_lowpart (<ssehalfvecmode>mode, operands[1])));
-  emit_insn (gen_reduc_<code>_scal_<ssehalfvecmodelower> (operands[0], tmp2));
+  rtx tmp3 = gen_reg_rtx (<ssehalfvecmode>mode);
+  emit_insn (gen_vec_extract_hi_<mode> (tmp, operands[1]));
+  emit_insn (gen_vec_extract_lo_<mode> (tmp2, operands[1]));
+  emit_insn (gen_<code><ssehalfvecmodelower>3 (tmp3, tmp, tmp2));
+  emit_insn (gen_reduc_<code>_scal_<ssehalfvecmodelower> (operands[0], tmp3));
   DONE;
 })
 
@@ -3558,14 +3561,15 @@
   "TARGET_AVX2"
 {
   rtx tmp = gen_reg_rtx (<ssehalfvecmode>mode);
-  emit_insn (gen_vec_extract_hi_<mode> (tmp, operands[1]));
   rtx tmp2 = gen_reg_rtx (<ssehalfvecmode>mode);
-  emit_insn (gen_<code><ssehalfvecmodelower>3
-    (tmp2, tmp, gen_lowpart (<ssehalfvecmode>mode, operands[1])));
   rtx tmp3 = gen_reg_rtx (<ssehalfvecmode>mode);
-  ix86_expand_reduc (gen_<code><ssehalfvecmodelower>3, tmp3, tmp2);
+  emit_insn (gen_vec_extract_hi_<mode> (tmp, operands[1]));
+  emit_insn (gen_vec_extract_lo_<mode> (tmp2, operands[1]));
+  emit_insn (gen_<code><ssehalfvecmodelower>3 (tmp3, tmp, tmp2));
+  rtx tmp4 = gen_reg_rtx (<ssehalfvecmode>mode);
+  ix86_expand_reduc (gen_<code><ssehalfvecmodelower>3, tmp4, tmp3);
   emit_insn (gen_vec_extract<ssehalfvecmodelower><ssescalarmodelower>
-               (operands[0], tmp3, const0_rtx));
+               (operands[0], tmp4, const0_rtx));
   DONE;
 })
 
@@ -3637,11 +3641,12 @@
  ""
 {
   rtx tmp = gen_reg_rtx (<ssehalfvecmode>mode);
-  emit_insn (gen_vec_extract_hi_<mode> (tmp, operands[1]));
   rtx tmp2 = gen_reg_rtx (<ssehalfvecmode>mode);
-  rtx tmp3 = gen_lowpart (<ssehalfvecmode>mode, operands[1]);
-  emit_insn (gen_<code><ssehalfvecmodelower>3 (tmp2, tmp, tmp3));
-  emit_insn (gen_reduc_<code>_scal_<ssehalfvecmodelower> (operands[0], tmp2));
+  rtx tmp3 = gen_reg_rtx (<ssehalfvecmode>mode);
+  emit_insn (gen_vec_extract_hi_<mode> (tmp, operands[1]));
+  emit_insn (gen_vec_extract_lo_<mode> (tmp2, operands[1]));
+  emit_insn (gen_<code><ssehalfvecmodelower>3 (tmp3, tmp, tmp2));
+  emit_insn (gen_reduc_<code>_scal_<ssehalfvecmodelower> (operands[0], tmp3));
   DONE;
 })