Modified: trunk/Source/_javascript_Core/ChangeLog (195925 => 195926)
--- trunk/Source/_javascript_Core/ChangeLog 2016-01-31 11:41:44 UTC (rev 195925)
+++ trunk/Source/_javascript_Core/ChangeLog 2016-01-31 11:41:52 UTC (rev 195926)
@@ -1,3 +1,21 @@
+2016-01-31 Guillaume Emont <[email protected]>
+
+ [mips] don't save to a callee saved register too early
+ https://bugs.webkit.org/show_bug.cgi?id=153463
+
+ If we save $gp to $s4 in pichdr, then in some cases, we were
+ overwriting $s4 before LLInt's pushCalleeSaves() is called (as pichdr
+ is at the very beginning of a function). Now we save $gp to $s4 at the
+ end of pushCalleeSaves().
+
+ Reviewed by Michael Saboff.
+
+ * offlineasm/mips.rb:
+ * llint/LowLevelInterpreter.asm:
+ Move the saving of $gp to $s4 from pichdr to pushCalleeSaves(). Take
+ the opportunity to only save $s4 as we never use the other callee
+ saved registers.
+
2016-01-30 Commit Queue <[email protected]>
Unreviewed, rolling out r195799 and r195828.
Modified: trunk/Source/_javascript_Core/llint/LowLevelInterpreter.asm (195925 => 195926)
--- trunk/Source/_javascript_Core/llint/LowLevelInterpreter.asm 2016-01-31 11:41:44 UTC (rev 195925)
+++ trunk/Source/_javascript_Core/llint/LowLevelInterpreter.asm 2016-01-31 11:41:52 UTC (rev 195926)
@@ -430,8 +430,10 @@
const CalleeSaveRegisterCount = 0
elsif ARM or ARMv7_TRADITIONAL or ARMv7
const CalleeSaveRegisterCount = 7
-elsif SH4 or MIPS
+elsif SH4
const CalleeSaveRegisterCount = 5
+elsif MIPS
+ const CalleeSaveRegisterCount = 1
elsif X86 or X86_WIN
const CalleeSaveRegisterCount = 3
end
@@ -449,12 +451,10 @@
elsif ARMv7
emit "push {r4-r6, r8-r11}"
elsif MIPS
- emit "addiu $sp, $sp, -20"
- emit "sw $20, 16($sp)"
- emit "sw $19, 12($sp)"
- emit "sw $18, 8($sp)"
- emit "sw $17, 4($sp)"
- emit "sw $16, 0($sp)"
+ emit "addiu $sp, $sp, -4"
+ emit "sw $s4, 0($sp)"
+ # save $gp to $s4 so that we can restore it after a function call
+ emit "move $s4, $gp"
elsif SH4
emit "mov.l r13, @-r15"
emit "mov.l r11, @-r15"
@@ -479,12 +479,8 @@
elsif ARMv7
emit "pop {r4-r6, r8-r11}"
elsif MIPS
- emit "lw $16, 0($sp)"
- emit "lw $17, 4($sp)"
- emit "lw $18, 8($sp)"
- emit "lw $19, 12($sp)"
- emit "lw $20, 16($sp)"
- emit "addiu $sp, $sp, 20"
+ emit "lw $s4, 0($sp)"
+ emit "addiu $sp, $sp, 4"
elsif SH4
emit "mov.l @r15+, r8"
emit "mov.l @r15+, r9"
Modified: trunk/Source/_javascript_Core/offlineasm/mips.rb (195925 => 195926)
--- trunk/Source/_javascript_Core/offlineasm/mips.rb 2016-01-31 11:41:44 UTC (rev 195925)
+++ trunk/Source/_javascript_Core/offlineasm/mips.rb 2016-01-31 11:41:52 UTC (rev 195926)
@@ -1041,7 +1041,6 @@
$asm.puts "sltu #{operands[0].mipsOperand}, #{operands[1].mipsOperand}, #{operands[2].mipsOperand}"
when "pichdr"
$asm.putStr("OFFLINE_ASM_CPLOAD(#{MIPS_CALL_REG.mipsOperand})")
- $asm.puts "move #{MIPS_GPSAVE_REG.mipsOperand}, #{MIPS_GP_REG.mipsOperand}"
when "memfence"
$asm.puts "sync"
else
